I'm not going to 'upgrade' to Windows 7 for several reasons.
1. I have an Epson printer and Epson Scanner - neither of which are very old. I searched on Epson's website to see if they had Win. 7 drivers for these devices and found none. I contacted Epson and they informed me that they will not be producing drivers for the printer or scanner. So, not only would have to buy a copy of Windows 7, I would have to buy a new printer and scanner!

2. Several other programs which I use on a regular basis, work perfectly well with XP but will not work on Windows 7. I know this having tried them on a friend's PC, running Windows 7.

3. I very much doubt if the Technics software (Song Manager, SD Jukebox and Fred's SDExplorer) will work with Windows 7. I haven't had a chance to try these programs on my friend's PC, but hope to do so in the near future.

I believe Vista had an 'XP Compatiblity' mode but how well this worked, I don't know. Whether Windows 7 also includes this facility I'm not sure.
So, for the forseeable future, I'll stick with Windows XP - it does everything I want and seems to be very stable, now that Microsoft have ironed out most of the bugs and plugged many security holes.