Pros: I switched over to Vista 64bit Ultimate as soon as it was available last year. I have had absolutely 0 problems with the new GUI or hardly any compatibility issues for what I do with my computer. I have used 4 gigs or 2 gigs of memory and haven't seen any difference in performance as I already max out my performance score at 5.9 I believe it was. Is the O/S more bloated than XP, yes but it contains many more features and programs, I especially like the backup program, media center and a host of new programs that XP didn't offer.

Cons: None that I have encountered other than a few manufacturers haven't made drivers for 64 bit and only 32 bit. I am building a secondary computer as we need one anyway and that is why I am putting the 32 bit version on it

Overall Review: Despite all of the negative reviews of Vista, I take my hat off to Microsoft for all of the work that went into this O/S. I personally find the change refreshing and rewarding to own, use and operate.

Pros: works just fine.Run very smothhhhhhhhhh.Works really great with my Counter Strike Source.

Cons: after upgrade been made,does not recognise my dvd drive & memory card reader. So i try to upgrade my dvd drive,finally it recognised my drive.SO far so good. Only 3327MB appears on my system.

Overall Review: Instaled with:Asus P5k-VM,GeForce8600GTS,Intel Core 2 Quad Q6600,Mushkin 4GB(2x2Gb)DDR2 800,Raptor WD1500ADFD,WD7500KSRTL,Asus DRW-2014L1T.

Pros: Lots of eye candy. Easy installation. Found all of my hardware right away.

Cons: Still has compatibility issues.

Overall Review: I had issues with my sound card, but I blame Creative Labs for that, not MS. I also has issues with games that have certain copy protection software and Vista wouldn't let them run. Again, not MS's fault and no patch for the games to dump the copy protection. In the end though, I ended up going back to XP Pro.

Pros: Looks good. Runs good. Now crashes less often than my work laptop running XP.

Cons: Driver support was poor. Occasionally incompatible with older software. Security and permissions can be confusing.

Overall Review: Bought this a little more than a year ago, and with all of the negative press that it was receiving, I decided to build a dual-boot system (Vista and Windows XP). It was tough going for about 2 months with driver issues for the network interface (slow and spotty connection), memory issues (crashed with more than 2GB installed), and video driver problems. Once ASUS corrected their drivers and fixed the bios to stop the memory crashes, and NVIDIA fixed their video drivers, it has been great. I am not sure if I would install this on older hardware, but on my one-year old stuff it runs really well. Most of the software I run works fine (even the older stuff) and I only run Windows XP to run one older program. If you are building new, don't hesitate to run Vista (but don't forget to update your drivers right away). My System: AMD Athlon 64 X2 6000+ Windsor 3.0GHz ASUS M2N-SLI Deluxe AM2 nForce 570 MB 4 GB RAM 2 500GB Seagate HDs (Raid 1) 2 EVGA 8600 GTS in SLI mode

Pros: The backup image feature in Vista Ultimate is fantastic. It by itself is almost worth upgrading from Home Premium. Microsoft has has taken security serious in Vista. The annoyances people complain about are the say ones that keep your computer far safer than it ever was with XP.

Cons: Those "are you sure you want to x, y and z" popup windows do get annoying at times, but the added security they provide balances them out. Windows took a step backward in their file backup utility (different from the image backup). I guess it's a bit easier for a novice to use though. To me that's a minor flaw since I use another program for my backups.

Overall Review: Vista has gotten an undeservedly bad rap in a lot of regards. If you remember when XP came out, you had to run the compatibility test to see which hardware and software weren't going to work with XP. Vista was/is the same way. It's to be expected though. Having a more powerful and high tech OS means you're going to need newer and more powerful hardware. I've been using Vista since it first came out and haven't even once thought about going back to XP.

Pros: Better memory management, improved user interface, tightened security, and more free software. Latest favorite: Windows Photo Gallery. Manage your photos by sorting, storing, tagging, naming, rating, and many other options. Makes storage simple and easy and downloads images from cameras directly.

Cons: Security dialogs can be a pain.

Overall Review: Worth the price for a new install. Not sure about upgrading, though. Also, was a little hesitant about all of the bad press. However, I haven't had a single problem with any software or peripheral.

Pros: It's Microsoft's latest. Alot of nice features. I had no real problems installing or updating. I believe it is more stable. I've only been running it a month, so far I'm not dissappointed. If your happy with XP you will like Vista. DO YOU RESEARCH! Newegg is the only place to get your computer needs.

Cons: It's Microsoft's latest. 32bit will not recognize beyond 3Gigs of ram. It's a bit of a pain in the *** (more of an annoyance) to update drivers and other software. DO YOUR RESEARCH!

Overall Review: I built my computer a little over a year ago. Started with XP, planned on updating to Vista. I bought a second HDD and did a clean install with a dual boot configuration. I did a lot of research and it all went pretty much to plan. My only regret is not getting the retail version so I could try both 32 and 64bit. DO YOUR RESEARCH AND PREPARE! I think most who are having problems are not prepared and have not checked for compatability. I'm not a gamer. Asus P5B-E, 6400 Core2 Duo, 4Gigs GSkill, 2-WD250 HDD Sata

Pros: More compatibility with older hardware and software.

Cons: I purchased this, but then decided not to use it, I instead got the 64 bit version, and I have no regrets. Unlike the retail version (which comes with 32 and 64 bit disks), this only comes with the one you buy. I would suggest the 64 bit version if you building a new system. I have had no compatibility problems with any new hardware, and all of my old programs seems to run fine. Plus, with 32bit, you can only have about 3GB of ram (the exact amount is dependent on your hardware). I wanted to start with 4 anyway, but even if you go with 2gb, RAM is one of the first/cheapest/easiest ways to squeeze another year or two out of an older machine. I fully expect to be upgrading to 8gb before I retire this computer, I would be toast with 32bit.

Overall Review: If you are buying the OEM version, you are likely building a new machine anyway, no better time to jump to 64bit.