I have a 4gig PC Quad Duo processor with Vegas Pro 9c + Prodad Mercali, Adorage & Heiroglyph + New Blue plug-ins.

The only plug-in I have is UltimateS 4, and it works...

If I instal Windows 7 64bit how many of those will still work?

Can't answer for the other ones...

I know there is a 64bit version of Vegas but what about all those plug-ins?

I was very pleased to see that we could use 64bit with our same serial number!

Can I load an earlier 32bit Vegas project into the 64bit version?

I'm doing it. Renders are 6 +/- times faster!! Creating the audio on the timeline doesn't seem to have changed at all.

What other problems may I encounter? (Eg, I still want to be able to use MS Office apps & Photoshop etc)

I am using Office 2007. The only problem I ran into was not having a font in W7 that I was using in Vista. Copied it over and all was well!!

I am currently dual booting between W7 64 and Vista 32. Gonna keep that up until I find out what does and doesn't work. Looking forward to my first "real" render though. Faster than real-time!!

Dave