Windows 10 F8 Safe Mode Boot

Follow steps below to enable F8 safe mode boot (applies to Windows 10 and 8.1):

  1. Boot PC using Windows 10 (8.1) iso USB flash drive or DVD
  2. Click Next to skip the first screen
  3. Press Shift + F10 To open advanced Command prompt window

Type the following command to enable F8 Safe Mode boot key:

bcdedit /set {default} bootmenupolicy legacy

Type Exit and press Enter to quit the Command Prompt. Remove your usb flash drive or DVD and turn your computer off. When you start your PC, you can now press F8 to get the Advanced Boot Options menu




Create macOS install usb using Linux

If you don’t have a spare Mac or your Mac is too old to download macOS from the Apple App Store then use the method below.

Create account on

The download required macOS from

Insert a usb (16GB+ recommended) into Linux PC usb port and run Terminal

Use fdisk to determine your usb dev name letter, e.g. /dev/sdc. It is very important to note the correct device letter or you may overwrite your own system or data drive!

sudo fdisk -l

Use dm2img to copy macOS (OS X El Capitan in this example) to your usb device (sdc in this example). This completely overwrites whatever is on the usb drive already!

sudo apt install dmg2img  # install dmg2img if not installed

sudo dmg2img -v -i ./EL_Capitan.dmg  -o /dev/sdc
Output from dmg2img...
dmg2img v1.6.7 (c) vu1tur (

./EL_Capitan.dmg --> /dev/sdc

reading property list, 361779 bytes from address 6237611619 ...
partition 0: begin=192, size=430, decoded=284
partition 1: begin=908, size=430, decoded=284
partition 2: begin=1611, size=356137, decoded=239844

opening partition 0 ...         [2] 100.00%  ok
opening partition 1 ...         [2] 100.00%  ok
opening partition 2 ...      [5991] 100.00%  ok

When complete eject the usb to flush IO buffers (important!) by clicking on the usb icon on the desktop and click remove | eject.

Insert usb in your Mac and power-up holding down the Alt | Option key until the Install usb icon is displayed in the middle of the screen.

Select the install usb to install macOS

Once in Recovery mode select Disk Utility to erase disk (if new drive or clean install)

Exit Disk Utility

Select mac OS to install from main menu and install to your main HDD or SSD

Note: the download source above is not Apple approved. To be safe, once your Mac is up and running, download the mac OS again from the Apple Store and re-create the install usb and carry out a clean install.


Useful Linux Terminal Commands

Display details about firmware, cache, memory

$ sudo lshw -C memory
       description: BIOS
       vendor: FUJITSU // Phoenix Technologies Ltd.
       physical id: 0
       version: 6.00 R1.06.3012.A1
       date: 04/21/2011
       size: 110KiB
       capacity: 4032KiB
       capabilities: pci pnp upgrade shadowing escd cdboot bootselect int13floppynec int13floppytoshiba int13floppy360 int13floppy1200 int13floppy720 int13floppy2880 int5printscreen int9keyboard int14serial int17printer int10video acpi usb ls120boot zipboot biosbootspecification
       description: L1 cache
       physical id: 5
       slot: L1 Cache
       size: 64KiB
       capacity: 64KiB
       capabilities: burst synchronous internal write-through data
       configuration: level=1
       description: System Memory
       physical id: 2a
       slot: System board or motherboard
       size: 16GiB
          description: DIMM DDR3 Synchronous 1067 MHz (0.9 ns)
          product: 99U5471-021.A00LF
          vendor: Toshiba
          physical id: 0
          serial: DE131F7C
          slot: Slot-1
          size: 4GiB
          width: 64 bits
          clock: 1067MHz (0.9ns)

Test and Benchmark 3D Graphics

sudo apt install glmark2

Command Prompt

Some less well known Windows 7, 8.1, 10 Terminal (cmd) commands

Command Description
powercfg /batteryreport Detailed battery diagnostics >  html
netsh wlan show wlanreport WLAN data last 3 days > html
Alt+Enter Full screen mode
F7 List previous commands
doskey /history > c:\cmd.txt Save command history to \cmd.txt to view last saved history session
msinfo32 System Summary  >  BIOS version amongst others
findstr /s dinosaur *.txt Search inside your files with findstr add /s to search subfolders
sfc /scannow
Fixes corrupted system files by replacing them with fresh ones from the local  Windows recovery image
dism /online/cleanup-image /checkhealth
Check the health of the recovery image. If you see a message saying corruption has occurred run command below
dism /online /cleanup-image /restorehealth
Fix recovery image. Only run if you have Checkhealth errors
Switch to Powershell in same window
start powershell  Start Powershell in a new window
 Get-AppXPackage -AllUsers | Foreach {Add-AppxPackage -DisableDevelopmentMode -Register “$($_.InstallLocation)\AppXManifest.xml”} Powershell command to reinstall Microsoft Store core Windows 10 apps
cipher /e c:\Vault
Replace “c:Vault” with the Folder or file to encrypt. To unencrypt right-click folder or file, select Properties; Advanced and untick “Encrypt contents to secure data” option.
shutdown /r /o
Boot to Windows 10 advanced options
netsh wlan show profile
netsh wlan show profile WiFi-name key=clear
Recover forgotten WiFi password. Replace WiFi-name with the one shown in list of network names (1st command). Scroll through results to see password shown against WiFi-name
 robocopy c:\users\username\Documents d:\backup\Documents /mir /copyall /dcopy:T /r:0 /w:0 /log:c:\users\username\log.txt /tee
Copy folders fast – mirror the source to the destination copying all files and folders, including empty ones +  all file attributes including NTFS permissions and copy timestamps and retry 0 times and wait 0 secs between retries and logfile and  log output to console and logfile


Create bootable usb using DD

This method depends on the iso file being designed as bootable, e.g Kaspersky Rescue Disk or Bitdefender Rescue CD, etc.

Plug in the USB flash drive and list its device name using fdisk

sudo fdisk -l
Disk /dev/sdc: 3.8 GiB, 4009754624 bytes, 7831552 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x052e500d

Device     Boot Start     End Sectors  Size Id Type
/dev/sdc1  *     2048 7831551 7829504  3.8G  c W95 FAT32 (LBA)

Unmount the device partition, e.g. sdc1.

umount /dev/sdc1

Copy the iso. file to the device (sdc) not the partition (sdc1). Note the larger block size (4M, default 512bytes) to speed up the transfer. The usb light will flash during copying. Note this can take a long time depending on iso file size. Be patient. When finished dd displays a summary report of bytes copied.

sudo dd if=filename.iso of=/dev/sdc bs=4M

Finally flush the io buffers and eject


sudo eject /dev/sdc

Gulp Sass suddenly rejecting double quotes

A slip-up of adding an extra ” to a string definition highlights an anomaly in Sass which causes it to flag every line of scss  code (including comments) with double quotes as an error including the real error lost in the jungle of errors. See example below with ” added to the end of $fontfamily (not easy to spot) and an excerpt of the Sass compiler error message pointing to valid line of code amongst many more misleading messages.

$fontfamily: "Comic Sans MS",Arial,Helvetica,sans-serif!important";
Error in plugin "sass"
Error: Invalid CSS after '...nd-image: url("': expected expression (e.g. 1px, bold), was "../images/Computer_"
on line 430 of src/scss/style.scss
>> // background-image: url("../images/Computer_Doctor_1800x1149.png");

All this confusion leaves you scratching your head trying to figure out what’s suddenly gone wrong leading you down false trails, e.g. thinking Sass has been updated to a buggy version or should I replace all double with single quotes or whatever.

Once you’ve tracked down the real error line and removed that extra ” all the other error messages miraculously disappear – phew!

I hope this  revelation saves you many hours of lost productivity.


Alternative DNS Addresses


OpenDNS (,

Google Public DNS (,

Cloudflare (,


OpenDNS 2620:0:ccc::2 and 2620:0:ccd::2

Google 2001:4860:4860::8888 and 2001:4860:4860::8844

Cloudflare 2606:4700:4700::1111 and 2606:4700:4700::1001.

Browsersync not Injecting or Refreshing page

If all else fails check for a commented <body> tag  before your <body> tag within the source code. Right-click the page and select View Page Source to eliminate this cause.


<!-- <body><script id="__bs_script__">//<![CDATA[
    document.write("<script async src='/browser-sync/browser-sync-client.js?v=2.26.3'><\/script>".replace("HOST", location.hostname));
//]]></script> -->

Browsersync appends its Java script after the first <body> tag it finds regardless of whether it is embedded in a comment or not! Obviously, being wrapped in a comment  effectively disables it from injecting or refreshing the page.



Ubuntu 18.04 Install WordPress in Home partition

­Install LAMP

For the purposes of this exercise the Apache document root will be moved to /home/mike/www/ and MySQL data directory moved to /home/mysql and a virtual host created called

Use Tasksel to install LAMP services

$ sudo apt install tasksel

Install latest Apache, MySQL and PHP servers

$ sudo tasksel install lamp-server

Configure Apache

Add user to Apache www-data group

$ sudo useradd -G www-data mike

Prepare new document root

$ mkdir /home/mike/www
$ sudo rsync -av /var/www/html /home/mike/www

Note: rsync – be sure there is no trailing slash on the source directory. When there’s a trailing slash, rsync will dump the contents of the directory into the destination directory instead of transferring it into a containing directory of the same name as the source, e.g. html.

Add Virtual Host

$ cd /etc/apache2/sites-available
$ sudo cp 000-default.conf
$ sudo nano /etc/apaches2/sites-available/


DocumentRoot /var/www/html


DocumentRoot /home/mike/www
<Directory /home/mike/www/wordpress/>
 Options Indexes FollowSymLinks
 AllowOverride All
 Require all granted

Save file.

Note: Directory directives explanation

  1. Options
    • Indexes – if a URL which maps to a directory is requested and there is no DirectoryIndex (e.g., index.html) in that directory, then mod_autoindex will returns a formatted listing of the directory WordPress .htaccess code redirects this to index.php
    • FollowSymLinks – the server will follow symbolic links in this directory, e.g. Permalinks
  2. AllowOverride All – allow the use of .htaccess to override Apache global settings for this directory
  3. Require all granted – access to directory is allowed unconditionally to avoid permission errors

Use a2ensite to enable site – creates software symbolic link in /etc/apache2/sites-enabled

$ sudo a2ensite

Disable the Apache default site (/var/www/html)

$ sudo a2dissite 000-default.conf

Enable Apache2 mod_rewrite module to allow modification of URLs

$ sudo a2enmod rewrite

Create .htaccess file and add WordPress rewrite code support

Now that Apache is configured to allow rewrites through .htaccess files, we need to create it in the site root folder.

Create empty .htaccess file

$ touch /home/mike/www/wordpress/.htaccess

Add web server (www-data) group ownership:

$ sudo chown :www-data /home/mike/www/wordpress/.htaccess

$ nano /home/mike/www/.htaccess

Add the following code:

# BEGIN WordPress

RewriteEngine On
RewriteBase /wordpress/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /wordpress/index.php [L]

# END WordPress

Note: WordPress adds/updates the above .htaccess code when Permalink Settings > Post aliases are changed. e.g, name.

Once modified save and exit.

Note: If WordPress were installed directly in the document root directory the rewrite codes would be:

# BEGIN WordPress

RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]

# END WordPress

For increased security set .htaccess permission to read only.

$ chmod 644 /home/mike/www/.htaccess

644 is normally required and recommended for .htaccess.

Test Apache2 configuration changes

$ sudo apachectl -S

To suppress AH00558 error
AH00558: apache2: Could not reliably determine the server’s fully qualified domain name, using Set the ‘ServerName’ directive globally to suppress this message

Add Servername directive to Apache2 global configuration file

$ sudo nano /etc/apache2/apache2.conf



Save and exit and test again

$ sudo apachectl configtest

Reports “Syntax OK” when no errors found

Restart Apache2 to effect changes

$ sudo systemctl restart apache2

Configure MySQL

Move MySQL data directory to /home/mike/mysql

Check current root is /var/lib/mysql/

$ mysql -u root -p
mysql> select @@datadir;


| @@datadir |
| /var/lib/mysql/ |
1 row in set (0.00 sec)

mysql> exit;

Stop MySQL

$ sudo systemctl stop mysql

Copy data directory to /home/mysql

$ sudo rsynch -av /var/lib/mysql /home

Backup original mysql folder by renaming it

$ sudo mv /var/lib/mysql /var/lib/mysql.bak

Point mysql data directory to new home folder location

Edit the MySQL configuration file

$ sudo nano /etc/mysql/mysql.conf.d/mysqld.cnf

Find “datadir” and change the path form /var/lib/mysql to /home/mysql

Edit AppArmor alias file to let MySQL write to the new directory by creating an alias between the default directory and the new location.

$ sudo nano /etc/apparmor.d/tunables/alias

Add the following alias rule to the end of the alias file

$ alias /var/lib/mysql/ -> /home/mysql/,

Restart AppArmor

$ sudo systemctl restart apparmor

Restart MySQL

$ sudo systemctl restart mysql

Verify status

$ sudo systemctl status mysql

Create WordPress Database and Admin User

$ mysql -u root -p
mysql> CREATE DATABASE pcdocgo_db;
mysql> CREATE USER mike@localhost IDENTIFIED BY 'password';
mysql> GRANT ALL PRIVILEGES ON pcdocgo_db.* TO mike@localhost;
mysql> EXIT;

Install WordPress

Download latest WordPress and extract to ~/wordpress

$ cd ~
$ wget
$ tar xzvf latest.tar.gz

Configure WordPress

$ cd ~/wordpress
$ cp wp-config-sample.php wp-config.php

Download WordPress Secure Keys and add to wp-config.php

$ curl -s

Copy output to Paste buffer

$ nano wp-config.php

Overwrite dummy values section below with Paste buffer

. . .
#define('AUTH_KEY', 'put your unique phrase here');
#define('SECURE_AUTH_KEY', 'put your unique phrase here');
#define('LOGGED_IN_KEY', 'put your unique phrase here');
#define('NONCE_KEY', 'put your unique phrase here');
#define('AUTH_SALT', 'put your unique phrase here');
#define('SECURE_AUTH_SALT', 'put your unique phrase here');
#define('LOGGED_IN_SALT', 'put your unique phrase here');
#define('NONCE_SALT', 'put your unique phrase here');
. . .

Replace DB_NAME, DB_USER, and DB_PASSWORD values with database, user and password values:

// ** MySQL settings - You can get this info from your web host ** //
/** The name of the database for WordPress */
define('DB_NAME', 'pcdocgo');

/** MySQL database username */
define('DB_USER', 'mike');

/** MySQL database password */
define('DB_PASSWORD', 'password');

Once complete, save and close wp-config.php

Prepare  WordPress directory

Copy content

$ sudo rsync -avP ~/wordpress /home/mike/www

Configure Permissions

$ cd /home/mike/www

Assign ownership values

$ sudo chown -R mike:www-data *

Create Uploads directory

$ mkdir /home/mike/www/wp-content/uploads

Allow Apache to write to this directory

$ sudo chown -R :www-data /var/www/html/wp-content/uploads

Complete WordPress Installation via Web Interface

In web browser, navigate to localhost


For new installs you will see the WordPress initial configuration page, where you will create an administrator account. Fill out the information for the site and the administrative account information. When finished, click on the Install WordPress button. WordPress will confirm the installation, and then ask you to log in with the account just created

Change the Permalink Settings to Post name

Adjust the permalink settings through the WordPress administration interface. On the left-hand side, under the Settings menu, select Permalinks and click the Post name radio button. Click “Save Changes” to generate the .htaccess rewrite rules.


NPM Rebuild

Delete node_modules folder and execute npm install