feat: ✨ Add BitLocker section for installation

Additions to the installation.md file and creating a guide with descriptive images to re-enact a common issues for laptop uses where there Windows installation is OEM stock.

docs/getting-started/installation.md

@@ -121,6 +121,7 @@ However, your old installation (including user data) will be copied to a `Window
 1. Right-click the ISO file we downloaded previously, clicking **Open With** :material-arrow-right: **File Explorer**. This will mount it to your File Explorer
 
 2. Under **This PC**, there should be an option for this ISO. Open it, then proceed to the `sources` folder, and open `setup.exe`
+    - For many retail Windows 11 laptops, BitLocker comes pre-installed, encrypting all drives on the machine. The message ["Make sure BitLocker Drive Encryption is suspended"](../assets/images/bitlocker-error-setup.jpg) will appear when you attempt to execute the `setup.exe`. Refer to our [BitLocker decrypting instructions]() to resolve this.
 
 3. Click **No thanks** to the updates, and uncheck **I want to help make the Windows installation better**
 

docs/troubleshooting/decrypting-bitlocker.md

@@ -0,0 +1,21 @@
+---
+description: A guide on how to decrypt your system drive using BitLocker
+icon: material/lock-check
+---
+
+# Decrypting a BitLocker encrypted drive
+
+BitLocker is pre-installed and configured to encrypt drives on a large number of retail notebooks, particularly Windows 11 laptops.
+
+To run the `setup.exe` file in the `sources` folder, we will be focusing on decrypting the `C:` drive, sometimes known as the "system" drive.
+
+!!! warning "BitLocker data loss"
+    BitLocker is a powerful encryption tool, and using it improperly may result in data loss. It is safe to follow these instructions, but failure to follow steps may result in loss of data.
+
+1. Run `CMD` (Command Prompt) with **Administrator privileges**
+2. Type `manage-bde -off C:` this will then start BitLocker with the parameters we entered
+    - Many users will see: [ERROR: This volume stores external key(s) that can automatically unlock other volumes.](../images/bitlocker-error-decrypting.jpg). If this applies to you, type `manage-bde -autounlock - ClearAllKeys C:` to clear the keys. After completion, re-type manage-bde -off C: to continue decrypting.
+3. If you got "Decryption is now in progress." you have completed the steps correctly. It will take some time to fully decrypt the drive
+4. You can checkthe progress b
+y typing `manage-bde -status` and finding the `C:` drive and the [percentage encrypted](../assets/images/bitlocker-error-decrypting.jpg).
+5. When the decyption percentage reaches "0%" you've successfully decrypted the drive!

mkdocs.yml

@@ -160,11 +160,12 @@ nav:
         - Windows Settings: getting-started/post-installation/configuration/windows-settings.md
         - Security: getting-started/post-installation/security/index.md
       - Software:
-        - Index: getting-started/post-installation/software/index.md 
-        - Web Browsers: getting-started/post-installation/software/web-browsers.md 
+        - Index: getting-started/post-installation/software/index.md
+        - Web Browsers: getting-started/post-installation/software/web-browsers.md
   - Troubleshooting:
     - Removed features: troubleshooting/removed-features.md
     - Scripts: troubleshooting/scripts.md
+    - Decrypting using BitLocker: troubleshooting/decrypting-bitlocker.md
     - Common Issues:
       - Atlas folder missing: troubleshooting/common-issues/atlas-folder-missing.md
       - Adobe Acrobat fails to install: troubleshooting/common-issues/adobe/acrobat-fails-to-install.md