hi, i recently installed thief 2 after playing and enjoying the first one, when i decided to look into playing the second thief game however i saw a lot of people recommending t2fix and i decided to try and install it but i've been running into this weird error that i haven't seen anyone else have, i tried both t2fix lite and the original t2fix and frankly i dont know what to do, if somebody knew a solution it would be much appreciated

This seems a permissions-related issue to me. You are probably trying to install the patch into a protected directory.
What directory you installed the game into?

its a folder within the documents folder, i didnt know that was a also a protected folder, where should i install it? (sorry if i explained myself badly, english ain't my main language)

Have you installed the game into a Documents subdirectory? In general this is not a good idea and I suggest you to check the permission of the installation folder.
If you installed the game as administrator, or as particular user, other users may not delete or modify the installation folder and its contents: I suspect that you are experiencing this situation.

C:\Games\T2\ would be the recommended installation folder.