Windows 10: Removing Synced files

I have a laptop that uses the same Microsoft log in as my mom's PC. At some point, her PC synced to my laptop. She isn't sure how that happened, but she is sure it was accidental. Now I have no room on my laptop because all of her files have transferred over. How do I fix this?

:)

 

Remove account

I suggest you backup your personalized files first before removing the account.
To delete an account, follow these steps:

1. Press WIN + X keys and click Command Prompt (Admin) from the menu.
2. Type the following command and press Enter. Replace test with the name of your sister's account. Code:

 

Recent File List

Remove-ItemProperty -Path "Registry::HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
\Applets\Paint\Recent File List" -name file1

Remove-ItemProperty -Path "Registry::HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
\Applets\Paint\Recent File List" -name file2
Remove-ItemProperty -Path "Registry::HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
\Applets\Paint\Recent File List" -name file3
Remove-ItemProperty -Path "Registry::HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
\Applets\Paint\Recent File List" -name file4
Remove-ItemProperty -Path "Registry::HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
\Applets\Paint\Recent File List" -name file5
Remove-ItemProperty -Path "Registry::HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
\Applets\Paint\Recent File List" -name file6
Remove-ItemProperty -Path "Registry::HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
\Applets\Paint\Recent File List" -name file7
Remove-ItemProperty -Path "Registry::HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
\Applets\Paint\Recent File List" -name file8
Remove-ItemProperty -Path "Registry::HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
\Applets\Paint\Recent File List" -name file9
...

you get the idea. ( too lazy to put it in a for loop and test it.

or just open regedit and remove all the fileX from that key.

 

OneDrive Sync Issue

Honestly, I don't understand why you haven't already tried to boot with WinPE or other live disk and manually remove the file? This example using Macrium WinPE boot disk, download Macrium Free and let it create a boot disk for you. Option to create one is shown automatically when you launch Macrium first time:

1. Switch to C: drive
   
2. Change the working folder to your OneDrive folder
   
3. Check that the file has no Read Only (r) and System (s) attributes set. As the file name in your case is quite long, you don't have to type the full name. Use the *.* wildcard to replace any number of characters in file name and any extension, in your case command attrib .849C*.* should be enough
   
4. If r and / or s attributes are shown for the file, remove them with command attrib .849C*.* -r -s
   
5. Check that attributes r & s are removed
   
6. Delete the file with del .849C*.*

(Steps 3 & 5 not necessary; step 3 because removing attributes as in step 4 removes them if set but does no harm if not set, and step 5 because the attrib command works for 100% sure if no error messages are given.)

The file should be removed now. You can test with command dir .849C*.*, it should not be shown anymore.