Just one comment regarding Dead Mtn. there have been problems with this one where you do not get the opening scene and the cursor does not move ... this was the fix that was found for this issue.
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Maybe and its worth a try but it sounds like for some reason your DivX Plus must be off. Try redownloading and installing it from this link and see if your Dead Mountaineers game starts to work again.
http://download.divx.com/divx/DivXInstaller.exe This is the fix that Ewil02 (a member here) discovered for those of us who had the same "no cursor" problem with the game. Hope it helps!