Fix Windows 10 Update Failures, e.g. Error 0x800f081f

Try running DISM and SFC commands to repair Windows system files. Once complete reboot and try running the update again.

DISM /Online /Cleanup-image /RestoreHealth

SFC /Scannow

DISM (Deployment Image Servicing and Management) manages both Windows Online and Offline Images and repairs system files

  • /Online switch instructs DISM to target the running Operating System instead of an offline Windows image (.wim) file or virtual hard disk (.vhd or .vhdx)
  • /Cleanup-Image switch performs cleanup and recovery operations on the running Operating System
  • /Restorehealth switch scans the running Operating System for corrupt files and attempts to fix them

SFC (System File Checker)

  • /Scannow will scan all protected system files, and replace corrupted files with a cached copy that is located in a compressed folder at %WinDir%\System32\dllcache

The above procedure also fixes Windows Defrag not running properly due to corrupt system files.

Change Windows 10 Users Folder Name

  1. Run ‘command prompt’ as administrator” and enter following
  2. net user Administrator /active:yes
  3. Sign out
  4. Log in with “Administrator” account. If newly activated wait up until Windows sets up the account
  5. From Start Menu right-click on Start Menu icon and select ‘Computer Management’
  6. If “Local users and groups” not listed run steps below to install Local User and Group Management (lusrmgr.exe) Console for Windows 10 Home
  7. Click on “Local users and groups”
  8. Click ‘Users’. Right-click on the Windows user name you want to rename and rename to the new name
  9. Close ‘Computer Management’ or lusrmgr program
  10. Open File explorer and go to ‘users’ folder. Right-click on the user folder and choose ‘rename’ and rename it to the new name
  11. Run ‘regedit’
  12. Select HKEY_LOCAL_MACHINE\ SOFTWARE\ Microsoft\ Windows NT\ CurrentVersion\ ProfileList
  13. Find the new named profile and double click on ‘ProfileImagePath’ and rename it to the new name
  14. Close ‘regedit’
  15. Signout and log in with new named account
  16. Open ‘File Explorer’
  17. Go to the ‘users’ folder to see ‘users’ folder has the new named user home folder
  18. Disable the Administrator account (note this does not delete the account)
    1. Run ‘command prompt’ as administrator” and enter following
    2. ‘net user Administrator /active:no ‘
    3. Close ‘command prompt’

Install Local User and Group Management (lusrmgr.exe) Console for Windows 10 Home

Download and install lusrmgr.exe program from Itectics and launch to get access to Windows Local User and Group management console. Continue from step 7 above.

Disclaimer: operations above run at the users own risk with no guarantees or responsibilities

Add .wps and .xlr Works associations to Office 2010 Starter Edition

Do the following (with Admin account) to associate .wps (Works document) and .xlr (Works spreadsheet) file types to Word and Excel.

  1. Create Restore point to roll-back in case you make a mistake editing the Registry
  2. Run Regedit
  3. Locate HKEY_CLASSES_ROOT \ .doc
  4. Right-click .doc key and select Export and save to Desktop file as, e.g. docassoc.reg. The contents should look like the sample below.
  5. Repeat steps 3-4 for .xls
  6. Exit regedit
  7. In file File Explorer Copy & Paste docassoc.reg renaming the target file to wpsassoc.reg
  8. Similarly create xlrassoc.reg using xlsassoc.reg as source
  9. Edit wpsassoc.reg and replace .doc with .wps and save
  10. Edit xlrassoc.reg and replace .xls with .xlr and save
  11. Double-click wpsassoc.reg and xlrassoc.reg to add the new keys to the Registry under HKEY_CLASSES_ROOT
  12. That’s it  – double-clicking .wps or .xlr files in File Explorer  will now open them in Word or Excel automatically. Also the file icons will change to recognisable Word and Excel files

Windows Registry Editor Version 5.00

"Content Type"="application/msword"




Windows Registry Editor Version 5.00

"Content Type"="application/msword"




Windows Registry Editor Version 5.00

"Content Type"="application/"




Windows Registry Editor Version 5.00

"Content Type"="application/"




  • In order to edit .wps or .xlr files in Office 2010 Starter Edition you have to first add the Works file converter. Later versions have this built in.

Disclaimer: The above procedure is carried out at your own risk and offer no guarantees

Add Suspend icon to the KDE Application Menu

To add the Suspend icon to the KDE Application Menu

  1. Click the KDE icon (bottom left hand corner) to bring up the Application Menu
  2. Click “Power/Session” on right-hand list to bring up list of Shutdown Options
  3. Right-click Suspend and select Add to Favorites

Similarly you can add or remove other shutdown icons.



HP 7520 WiFi scanning not working Mac OS High Sierra

If when installing an HP 7520 WiFi printer with HP Easy Start you get a warning that the scanner does not support “Bonjour” then you may end up with a working printer but no scanner!

In most cases this happens because you have a dual band router advertising 2.4GHz and 5GHz on the same SSIDs. In short the HP 7420 only works with the 2.4GHz network.

One solution is to disable the 5GHz network or rename it and only connect the Mac and printer to  the 2.4GHz SSID network. This may have to be done manually, i.e. entering WiFi password from the printer front panel. Once connected (ping test with printer ip address) uninstall the HP printer software using HP Uninstaller and reinstall the printer using HP Easy Start. This time you should not get the warning message and have both printer and scanner working.


Real World WiFi Speeds

Real World Wi-Fi Speeds

IEEE standard Wi-Fi Alliance Standard Theoretical Speed Real-world Speed
802.11ax Wi-Fi 6 10Gps 700Mbps
802.11ac Wi-Fi 5 1.3Gps 200Mbps
802.11n Wi-Fi 4 600Mbps 150Mbps

Wireless Broadband Alliance (WBA) real world trials carried out in the “hostile” environment of the Mettis Aerospace facility in the UK West Midlands.


Linux Content Search Tool

Use Catfish to find files and file content quickly – note content search only works for text type files. Use Recoll for other file types.

Install using Synaptic Package Manager or from Terminal as follows:

sudo apt install catfish

Run it by selecting it from from Utilities or use the Search function and enter Catfish to locate.

Once running you should see screen below.

To search for content first click the settings cog and check “Search File Contents”. This will then force Catfish to search for the string in the files within the top directory you have selected to the left of the search box. In this example we are searching for the content string “tooltip” within files in the the top folder “scss”. The number of hits (3) and files are displayed that contain “tooltip” in the main window. To open a file double-click it.

To search for file names only uncheck “Search File Contents”

Enable Windows F8 Safe Mode Boot Key

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

  1. Boot PC using Windows 10 or  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. double check the target device letter to avoid overwriting the wrong 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.

Insert usb in your Mac and when 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 again.

Alternative MacOS (English) Source

user:~$ cd Downloads/
mkdir macosdownload
git clone macOS-Big-Sur
Cloning into 'macOS-Big-Sur'...
remote: Enumerating objects: 5, done.
remote: Counting objects: 100% (5/5), done.
remote: Compressing objects: 100% (5/5), done.
remote: Total 991 (delta 0), reused 1 (delta 0), pack-reused 986
Receiving objects: 100% (991/991), 223.56 MiB | 1.29 MiB/s, done.
Resolving deltas: 100% (501/501), done.
Checking out files: 100% (94/94), done.
user:~$ ~/Downloads/macosdownload$ cd macOS-Big-Sur/

user:~/Downloads/macosdownload/macOS-Big-Sur$ ./
[+] Fetching
[+] Fetching
[+] Fetching
 #    ProductID    Version   Post Date  Title                                                                                                                               
 1    061-26578    10.14.5  2019-10-14  macOS Mojave
 2    061-26589    10.14.6  2019-10-14  macOS Mojave
 3    041-91758    10.13.6  2019-10-19  macOS High Sierra
 4    041-88800    10.14.4  2019-10-23  macOS Mojave
 5    041-90855    10.13.5  2019-10-23  Install macOS High Sierra Beta
 6    061-86291    10.15.3  2020-03-23  macOS Catalina
 7    001-04366    10.15.4  2020-05-04  macOS Catalina
 8    001-15219    10.15.5  2020-06-15  macOS Catalina
 9    001-36735    10.15.6  2020-08-06  macOS Catalina
10    001-36801    10.15.6  2020-08-12  macOS Catalina
11    001-51042    10.15.7  2020-09-24  macOS Catalina
12    001-57224    10.15.7  2020-10-27  macOS Catalina
13    001-68446    10.15.7  2020-11-11  macOS Catalina
14    001-79699     11.0.1  2020-11-12  macOS Big Sur

Choose a product to download (1-14):

This will download a .pkg file from which you can extract the .app require to create a bootable usb

  1. Right-click on the .pkg file > select “Show Package Contents”
  2. Open the Contents/SharedSupport folder and locate the file named InstallESD.dmg

For further information see:

Note: to get install version of app file open dmg file to copy app file to Applications folder