The server has SBS 2008 R2, 64 bit. It has 6 physical DIMM slots, four of which will be occupied by 2GB RDIMM (8 GB total).

I have some unused WinXP Pro licenses. My initial thought was to upgrade the XP Home computers to those. I have a few Vista Home computers, and you are right, maybe I should just go for Win7 instead of Vista Pro. I worry about whether the old boxes can run the newer OS without more hardware upgrades, availability of drivers etc. I have about 1/2 Dells, but some are really off brands. My main work computer in the exam room is an HP touch screen running Vista Home.

One consideration has always been money. That's why I got eBay server instead of going with Dell. Even with corporate discount, the cheapest usable server with 2008 foundation was about $2000, and that's 4GB memory and RAID1. I saw threads on this board for server quoted at $5000 and that's just not affordable. If I can get away with cheaper options for clients, I would love it. After all, they will all work fine, I hope. I wish Microsoft sold cheaper OS, Win7 foundation for $9 or something.