We have migrated to Win7 on our two primary machines. (Our Vista machines (3 of them) died unpleasantly.)

As mentioned above, one key to satisfactory operation on Win7 is sufficient RAM. The actual "recommended minimum is 4GB, not 1,although I'm not sure what minimum Microsoft claims the OS will "limp" with. (Even WinXP was rather sluggish with 1GB, unless your use was strongly on the wimp side. I had 4GB in my last WinXP machine, but that was what you needed to install to get the maximum usable, about 3.7?, for XP - or for 32 bit Vista.)

With both Vista and Win7 there is a very significant difference between "Home Basic" and "Home Premium" versions. The Home Basic omits nearly all of even the most rudimentary of "tools" necessary to keep things running. (Home Basic, I believe, even omits the "backup" functions, and has very limited capability for importing programs and settings from another computer.)

I have not seen a retailer in my area even offering new machines with less than the Home Premium Win7, or with less than 4GB RAM. Most, even of the cheaper machines, have Home Premium and (claim to have) 8GB RAM. Since the cheaper machines usually have "motherboard integral graphics" up to about 2GB of the 8GB they claim to have installed may be reserved for graphics, so you only expect about 6GB to show in SysInfo if there's 8GB on board.

Sellers here also are not stocking any 32 bit Win7 machines. Microsoft indicates 32 bit Win7 "runs" but strongly encourages using 64 bit only. If you run 32 bit Win7 you may have the same 4GB RAM limit (~3.7 usable) as for 32 bit Vista/WinXP.

If you're really concerned about compatibility with older programs and hardware, you probably would be well advised to go to the next step up from the Home Premium versions, which is necessary to get the "virtual machine" functions necessary for full "run as" function. Home Premium allows you to install older programs in "run as" mode to emulate earlier OS versions, but even though the programs will run, the security features in Win7 mean that you'll be constantly "giving permissions" for everything many older programs try to do. (Manufacturer's Certificates do expire, and Win7 is very fussy about the "current certificate status" of anything you install.)

I believe Microsoft still has the site up that will "examine" your computer and tell you if it's suitable for upgrade to Win7, but I suspect the machine has to have some operable OS in place in order to be probed. There are definitely Mickey sites with long lists of compatible/incompatible programs on display.

Moving from Vista to Win7 we haven't experienced any difficulties with printers, scanners, and the like; although the Win7 setup may have loaded new drivers when it found the devices. Win7 appears to include some "generic" drivers if it's necessary to replace an old incompatible one, and the one or two we suspect might have been installed seem to work reasonably well. Our printers/scanners are mostly recent models with Win7 compatibility assumed, although one 12 year old Canon that wasn't even "certified" for WinXP didn't see a problem. The device builders should be able to tell you if their existing drivers will work with Win7, and/or if there are driver updates for them; but that can get to be tedious to search out if you have quite a few to check.

John