QUOTE (krisnord @ Jul 18 2008, 07:02 AM)

But it refers to Mechanical and Inventor. I'm not sure if AutoCAD 2008 has 32 and 64...
I found this related to the error with AutoCAD:
acad.msi: AdskExecuteSequence
This error message indicates that there was a failure during the installation. In most cases, this error message does not provide an accurate diagnosis of the installation problem.
CCleaner found a lot of issues. I've used it two days now, and it always find things. But clearly not this error.
I had for example a startup-error, and this is gone now thanks to CCleaner.
As far as CCleaner Registry issues is concerned , be sure to keep scanning for issues until no more are found.
CCleaner is not a Registry "fixer". It identifies certain inconsistencies and tells the user what they are and what it will do to "fix" the inconsistency.
I think Hazel's link to that workaround is probably your best chance to get AutoCAD 2008 installed. It is not the fact that the AutoCad 2008 is 32 bit or 64 bit. The problem is with the install program from Autodesk itself. Apparently it is trying to use the 64 bit installer instead of the 32 bit one that is needed.
You need some tech help from Autodesk itself to get this resolved. With a price tag like that there should be plenty of help.

davey
P.S. Make sure that you are downloading from the Autodesk official site and not some unauthorized site.Many unofficial sites exist and can not be relied upon to the be latest and "clean" version. You don't want to be designing something with "spyware" as part of the package do you? The official version may already have the install problem fixed.