In all tests, 7 benchmarked faster. HOWEVER, in virtually all of these tests, the difference was only between several to around 20 percent. Such a difference is simply not noticeable for the vast majority of the basic applications that we use. This difference is also way too small to account for why some people "hate" Vista but "love" 7; instead, the explanation is that these people are comparing running 7 on modern (e.g. Core i) machines made in 2008-2012 versus running Vista on much older (e.g. Pentium 4) systems from 2001-2005.
My thoughts exactly, it's all very well getting bogged down in numbers and speeds in bench-marking applications, but really you can't tell the difference in the real world. Somebody tell me if they can tell the difference between gaming on a GTX 560 and then gaming on a GTX 560 Ti - I bet you could tell me some games get slightly higher FPS on the 560 Ti, but really, is 5 FPS more on certain games worth £50 more? I know we don't talk about graphics cards here really that much because after all this is a laptop forum, but it's the same sort of thing. If you have Vista and you're happy with it, why upgrade to Windows 7?
I also put Vista on an old T42 of mine with 2GB of RAM and it gave me about the same user experience; a little sluggish but nothing particularly frustrating.
I ran Vista on 2GB RAM on a P4 HT 3.0GHz and it was OK. Didn't really like my HP dx2200 that much, I've sold it now, but I didn't like that machine because XP ran like a dog on it (don't know why, even after a fresh install from an original XP Pro disc), Vista wasn't much better and 7 was a little faster than both but still sluggish. Not a great machine, not really fit for any Windows OS.
In light of the small performance differences among XP, Vista and 7 (for reasonably modern computers that is), my main criteria for deciding which one I like most are the user interface and security features. XP loses big time on both counts. 7 is somewhat more secure than Vista, but Vista trumps 7 in terms of the UI. I like my computing experience to be as pleasant as possible, and so I value the UI more than security and went with Vista.
XP's Luna interface looks outdated and old, certainly if you use XP make sure you use the Zune theme (free from Microsoft) or use the classic theme. Vista looks pretty, and is possibly prettier than Windows 7, but I prefer Windows 7's taskbar. As far as security goes, I know Vista's UAC is so annoying it makes you want to pull your hair out, but it does stop and make you think before you install programs, especially if they're from untrusted/unknown publishers. The UAC in Vista is too intrusive I think, and in Windows 7 the default setting is certainly much better, but I think you can change it in Vista anyway.
Your Athlon 64 3700+ has a PassMark score of 593. The slowest computer I have run 7 on is a Dell OptiPlex GX280 with 3.40GHz Pentium 4 (PassMark 550) and 3GB of PC2-4200 RAM.
It's not so much the CPU I was worried about, it was the graphics card (only being AGP) and the 1GB DDR RAM. I forget what speed this RAM runs at now, but it's slow. I'd say of all the components in the PC, the CPU was one of the stronger ones, graphics card second. GPU is a 6600 GT 128MB by the way. Did originally have a Sapphire Radeon X800 XT 256MB (much better card than this 6600), but the X800 died and I needed a cheap replacement and this 6600 GT for £12 was the cheapest decent AGP card I could find. Did find some 6800 Ultras on eBay, but these went for a lot more than £12. The 6600 does what I want it to do (play NFS Most Wanted and FS 2004) and NVIDIA still support these 6-series GPUs, so I can get the latest drivers, unlike AMD who no longer support the X800. I could still download a driver for the X800, but it's an old one from a few years back.
but if you must put 7 on it, definitely get 2 more gigs of RAM.
Most I can go is 1.5GB. My GA-K8VT800 PRO board has 3 bays on it, but two of these are already filled with 512MB each, and the spare 512MB stick I have runs slower than the two already installed, meaning my system would become slower, not faster. I've put XP into "best performance mode" (ie - classic interface), seems to have sped things up. Got a copy of XPx64 at my disposal, do you reckon I should install this and see if 64-bit XP is any faster than 32-bit? I know I've only got 1GB RAM, but you never know. Personally, I don't think it will be, but you never know.