For those of you keeping track, I have been having a persistent problem with Acrobat 8 installed on a recent vintage Dell, Windows Vista Ultimate laptop since May. The problem is that it hangs a couple of seconds after the program starts (both by starting the Acrobat executable directly and by opening a PDF document). This was not installed over version 7 (it was a new laptop). It worked for a few months, then the problem suddenly appeared (not incidental to any install or traumatic computer event--I wasn't using the laptop for a couple of weeks other than to check email).
I have tried numerous suggestions from Adobe Support, Dell, and found on the internet. A couple or three weeks ago I made a clean install of Vista, updated, then made a clean install of Acrobat 8 updated to 8.1, and had the same problem, so I inferred that a windows update caused the problem. I have always followed the instructions given by Adobe and elsewhere for fixing freezes (UAC on, administrator access, delete update folders, etc)., and have even gone so far as to manually delete all adobe-related subdirectories and registry entries in an attempt to make the next install work.
After reading recent posts in this forum, I disabled DEP, and still had the problem. WIth DEP disabled, I also uninstalled all Adobe Software, followed the instructions from Adobe for fixing freezes, and reinstalled, checked to see if it still froze (it did), then reinstalled the 8.1 update; and it still freezes at the same point. What I have NOT tried is a clean install of Vista followed by a clean install of Acrobat and the 8.1 update WITHOUT windows updates (someone else is trying that). And, in any case, running Windows Vista without DEP and un-updated on a computer connected to the internet is not, in my opinion, a good idea.
So, at least for my part, disabling DEP did not help.