My Lenovo ThinkCentre A55 runs just fine on Vista Business and I received Win 7 Ultimate NFR for both 32 and 64 bit versions. I have no real need to upgrade the OS, but I'm a tech junky and having the latest is one of my passions. Seriously, if I go more than a week without wiping and reloading some version of an OS on my BlackBerry, I start going into withdrawal. Anyhow, I'd like to put Win7 on my system, but just not sure if it's worth any potential headaches. I could upgrade to the 32 bit relatively easily I assume, but I'm thinking of doing a clean install of the 64bit. I would probably leave the recovery partition intact and install Win7 over the running Vista OS partition.

Is there any great advantage to loading 64bit from scratch? I have 4GB installed, and of course can only see 3GB currently. All programs and hardware are compatible per Windows Upgrade Advisor. I haven't done a clean install on my pc in a few years, and I remember it being a huge pain to re-install all programs and settings. Should I just go with the 32bit version?

The only other concern is that my A55 came with Office 2007 Pro installed and if I do a full install on Win7 64bit, I'll lose that, which would be very expensive to replace.

Thanks!

I've had Office running in 64 bit Vista. I didn't have any issues with it. As for 64 bit, I didn't really see any huge performance leaps running it, but I don't do anything really super CPU intensive or where I'd need more than 3GB of memory.

I've found x64 to be smoother, but I'm a power user and do a lot of stuff most people don't do. I've always been a fan of more ram. If you're not using all 4 gigs, might as well, right?

I've found drivers to be very very solid on win 7 or vista x64 (since both are are 95% interchangeable, I mention both). I have had no issue with software or hardware compatibility in any way.

I'd go x64. Actually, I did with both vista and win 7. I never looked back.

As for clean install, everything will run better, plus you can tweak everything from a stock OS to get the most performance out of your machine. How long does it really take to reinstall everything anyways?

I'd go x64.

Edit: Depending on how much ram you eventually want to have, if you can drop another 4 gigs in there and that won't break the bank, you can run without a page file and see a performance boost. I've never used more than 4gigs of ram unless I'm benchmarking.

Having previously running Vista x84 (32 bit), I also found the Vista x64 (64 bit) to be faster, smoother and above all, more reliable.

I've never actually run Windows 7 x84 or x64 before, but hey, I have a copy of Windows 7 Pro downstairs and maybe in the future, I'll be able to install it. If I do, then I'll be installing 64 bit edition. Windows 7 and Vista are in some ways, very much alike from what I can gather.