Something else I thought I'd add, some people recommend limiting Thief 3 to one CPU core but I don't agree as after installing it as I have (on many occasions and varying machines) it has worked without problem even on systems with 8 threads (4 cores plus Hyper Threading). Perhaps some ones installed differently have such problems though installing it as I've mentioned none of the machines had or have any such problems.
snobel: Hi, I'm the author of the Sneaky Upgrade patch mentioned here:
http://www.gog.com/en/forum/thief_series/thief_iii_tips_tricks_fixes.
I'd suggest that you try that first instead of those older patches, which it was made to replace. It's much easier to install, and contains some extras.
It also fixes the multicore issue, at least for the vast majority of players.
Sorry but I don't agree with you, I've tried that patch and have issues with the way it works and it has a broader focus changing more than just the desired widescreen options one may want.
For example if it doesn't want to work with the files of the installed Thief 3 game it tries to download them, making it useless if there is no internet connection on the PC it's being used on. Compared to the things I linked to which simply work with every install I've used them on without any problem and don't require downloading things from the internet so there's not problem using them in places that don't have internet access.
Also the others have no install, other than the widescreen one having to be run from the game folder, it doesn't get simpler than that.
XJDHDR: Wouldn't it be easier to simply disable this feature? Open the Windows Games explorer then click on the options button and change the options shown.
https://www.dropbox.com/s/9ibtcgdm2xda6gc/Game%20updates%20and%20options.gif Yes it would be if that worked, doing that and even disabling it and other relevant things via the registry don't always work to prevent it causing the problem I've mentioned and even when it does it's often short lived as the problem just starts up again later down the line. Out of more than 10 Windows 7 machines I've done it on (both 32 and 64bit) it's worked once maybe twice so it seems it's a luck of the draw presuming it doesn't start up again when trying to play another old game.
Edit,,,
Oh I remembered something else that can help in preventing that dreaded Game Explorer leading to rundll32.dll problem, if disabling the options in Game Explorer and other tricks still don't stop it from messing with your games starting you could try to unregister the gameux.dll from the command prompt (run > CMD) running this
on 32bit system
regsvr32 -u c:\windows\system32\gameux.dll
and for 64bit (64bit requires both these)
regsvr32 -u c:\windows\SysWOW64\gameux.dll
If wanted you can re-register them with these
on 32bit system
regsvr32 c:\windows\system32\gameux.dll
64bit system again needs you to run both
c:\windows\SysWOW64\gameux.dll
If all else fails you could stop rundll32.dll from being called by renaming (don't remove or delete it) this file C:\Windows\AppPatch\AcGenral.dll , then change it's name back when done playing.
With so many "solutions" out there to this Game Explorer nonsense from people who either aren't connected to the internet or have a secure system it's clear changing the settings in Game Explorer doesn't work for just me or the PC's I've tried it on then having to resort to other mesures.