Slow Startup Investigation Win 10

Kindly perform below steps & see if this helps you in anyway.

1) Uninstall the bitdefender product with add/ remove programs option in windows

2) To remove the remaining files download and run Bitdefender product uninstaller (https://www.bitdefender.com/files/KnowledgeBase/file/Bitdefender_2022_Uninstall_Tool.exe)

3) Restart PC in safe mode (https://support.microsoft.com/en-us/windows/start-your-pc-in-safe-mode-in-windows-92c27cff-db89-8644-1ce4-b3e5e56fe234)

4) As soon as desktop opens, assuming your windows drive is C, open below things in run (windows icon + R) command one by one :

C:\Program Files (delete any folder with name bitdefender)

C:\Program Files (x86) (delete any folder with name bitdefender)

C:\ProgramData (delete any folder with name bitdefender)

C:\Users\{your pc name}\AppData\Local (delete any folder with name bitdefender)

5) Open run command again and run below command one by one :

temp ,delete all the files in the folder

%temp% ,delete all the files in folder

prefetch ,delete all the files in folder

6) Open registry editor through run command (windows icon + R) and then type regedit. Once registry editor opens, click on edit -> find, make sure to tick mark match whole strings only. Type bitdefender in search box and click find next. If any file or folder under name of bitdefender is found, delete it. Continue searching the registry and deleting until the search will report no registry keys found.

7) Restart your PC in general mode by unticking the option that you selected to run the system in safe mode and then click apply.

8) Remove devices from online bitdefender central (https://www.bitdefender.com/consumer/support/answer/2795/)

9) Download online installer for your respective bitdefender product from below stated links

Bitdefender Antivirus Plus: https://download.bitdefender.com/windows/installer/en-us/bitdefender_antivirus.exe

Bitdefender Internet Security: https://download.bitdefender.com/windows/installer/en-us/bitdefender_isecurity.exe

Bitdefender Total Security: https://download.bitdefender.com/windows/installer/en-us/bitdefender_tsecurity.exe

Once your respective bitdefender product is installed, a bitdefender dialogue box will open where you will need to login with your registered bitdefender online central details and after a successful login, your product will be synchronized with your online bitdefender central account. Henceforth, your product will get registered & activated with online bitdefender central automatically.

If issue persists, 

Generate bitdefender support tool logs (https://www.bitdefender.com/consumer/support/answer/1733/)

Generate bitdefender connectivity logs (https://www.bitdefender.com/consumer/support/answer/9689/)

Share the logs & your query with bitdefender support team by dropping them an email at bitsy@bitdefender.com

The support team will reply back to your query within next 24-48 hours excluding weekends.

Regards