I have just clean installed Vista. It has SP1 on it but not a load of software. When I try to install Reader 9, setup unpacks up to 99.90% then I get an error message -Setup has stopped working. A problem caused the program to close unexpectedly.
I get the same problem trying to install the trial version of acrobat 9 pro.
I tried installing the software in safe mode but get the same problems.