Windows 7: Windows 7 Upgrade - failed

I tried to upgrade from Vista (64bit) to Windows 7 and it got up to generating compatibility Report - which was completely blank. The only way to proceed was to hit 'Close' - which then cancelled the installation!
Previous to this, I had also tried to download & run the Upgrade Advisor. When trying to run it, it just did nothing at all - didn't even open up. I disabled my Kaspersky anti-virus and disabled any Windows security. I was trying to avoid doing a clean install - but maybe only option. Any ideas?

You will be asked for your full system specs, so you might as well go ahead and give them.

Welcome to Seven Forums.

We're going to need a little bit more to go on.

Check this sticky thread and answer as many questions as possible. D/L the SIW program and give some more details on your system specs.
Questions to use for help with Installation Issues

Additional tutorials for installations can be found at Tutorial quick reference list for Installing Windows 7

Let us know some more information and we'll give you some suggestions.