Case Studies – PC Doctor Godalming

Remove Change Search Settings from Firefox Homepage Content Search Suggestion List

09/06/2025 by James

This fix works around the issue of Firefox randomly selecting “Change Search Settings” to search for the entered string in Firefox Settings when you want to search the web with the default search engine. When this happens you also lose the search string and have to retype it.

Place the following code in userContent.css or userChrome.css and place it in the chrome (lower case) folder within the Firefox default profile directory. If the chrome folder does not exist then create it.

* Update: best to have both userContent.css and userChrome.css in chrome folder as it is noticed that some pages,

Reset and Wipe your PC using Windows Reset

26/05/2025 by James

The simplest way to wipe your PC to donate, recycle, or sell your PC, is to use the Windows 10 | 11 Reset option

Windows 10
Settings > Update & Security > Recovery
Click ‘Get started’ under ‘Reset this PC’

Windows 11
Settings > Windows Update > Advanced options > Recovery
Click ‘Reset PC’

When ‘Reset this PC’ dialog opens, click ‘Remove everything’
Click reinstall Windows from ‘Cloud download’ or ‘Local reinstall’ (faster)
In ‘Additional settings”

List LAN IP Addresses Host Names MAC addresses and Owners

02/05/2025 by James

Linux script to discover active hosts and resolve IP, .local hostnames, MAC addresses, and owners

Install nmap and avahi-utils (if not already installed):

sudo apt update
sudo apt install nmap avahi-utils

Short nmap command to list IP, hosts, etc. but omits .local devices

sudo nmap -sn -R 192.168.1.0/24

# Terminal script to list IP Addresses, Host Names, MAC addresses and vendors
resolve_device() {
    local ip=$1
    echo "Resolving IP: $ip"
    local hostname=$(avahi-resolve -4 -a "$ip" 2>/dev/null | awk '{print $2}')
    if [ -z "$hostname" ];

Create Locally Trusted Host SSL Development Certificates

20/04/2025 by James

Use mkcert to making locally-trusted host development certificates that avoids browser self-certification dialog warning and requires little or no configuration

Install mkcert:

sudo apt update
sudo apt install libnss3-tools
curl -JLO "https://dl.filippo.io/mkcert/latest?for=linux/amd64"
chmod +x mkcert-v*-linux-amd64
sudo mv mkcert-v*-linux-amd64 /usr/local/bin/mkcert

Install the local CA:

mkcert -install

Generates and installs CA cert/key pair (rootCA-key.pem,rootCA.pem) in system trust store – $CAROOT (defaults to ~/.local/share/mkcert)
Installs local CA in the Firefox and/or Chrome/Chromium trust store (requires browser restart)

Generate certificate and key file for locally hosted website:

mkcert example.org localhost 127.0.0.1 ::1

Creates two files: example.org+3.pem (certificate) and example.org+3-key.pem (private key).

Enable 3rd Party SSD Trim in MacOS

25/03/2025 by James

Enabling TRIM for third-party SSDs is primarily done through the trimforce command in Terminal. Here’s a breakdown of the process and important considerations:

Understanding TRIM

TRIM is a command that allows the operating system to tell an SSD which data blocks are no longer in use and can be erased. This helps maintain the SSD’s performance over time.

Enabling TRIM

The trimforce command is the native way to enable TRIM in macOS High Sierra and later versions.

MAC Terminal command to stop indexing external drive

24/03/2025 by James

sudo mdutil -i off /Volumes/YourExternalDriveName

Explanation:

sudo: This command requires administrator privileges to modify system settings.
mdutil: This is the command-line utility for managing the Metadata Server, which handles Spotlight indexing.
-i off: This option tells mdutil to turn off indexing.
/Volumes/YourExternalDriveName: This is the path to your external drive. You must replace “YourExternalDriveName” with the actual name of your drive as it appears in the Finder or in the /Volumes directory.

Copy files with rsync on Mac

17/03/2025 by James

Use the power of rsync to ensure file creation dates are preserved whilst copying and the ability to restart if interrupted and automatically skip files which have already been copied

MacOS does come with a version of rsync pre-installed. However, this is normally an ancient version and needs the newer version installed to get the latest features, e.g. preserve creation times option or bug fixes. Here’s how you can typically achieve this on MacOS:

- Install Homebrew (package manager for macOS) :
  - Open Terminal.

Manually remove a printer on a Mac

10/03/2025 by James

Step-by-Step Instructions

Open System Settings:
- Click the Apple menu and choose System Settings.
Access Printers & Scanners:
- In the System Settings window, click on Printers & Scanners from the sidebar. You might need to scroll down to find it.
Select the Printer:
- Find the printer you want to delete in the list on the right side of the window.

Windows Clean Install

26/02/2025 by James

Steps to install a clean copy of Windows 10|11

Audit system set-up by taking screen-shots (Windows Key + Print Screen), e.g. desktop, installed programs, …
If not replacing drive create a System Image Backup to a USB drive and go to step 4
Replace drive
Boot latest Windows 10|11 iso version from USB
Clear drive partitions
Add Microsoft login account
Restore Windows settings, data and apps from Onedrive
Install Windows updates,

Bypass the windows 11 installation requirements

01/02/2025 by James

During the installation process, after confirming the keyboard type or before reaching the screen where it says your PC can’t run Windows 11.
Press Shift + F10 to open a Command Prompt window.
In the Command Prompt, type regedit and press Enter to open the Registry Editor. Now, navigate to HKEY_LOCAL_MACHINE\SYSTEM\Setup
Right-click on the Setup key, select New > Key, and name it LabConfig. Inside the LabConfig key, create new DWORD (32-bit) Value entries with the following names and values:

BypassTPMCheck and set its value to 1

BypassSecureBootCheck and set its value to 1

Create BypassCPUCheck and set its value to 1

Close Registry Editor and the Command Prompt,

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