I have a Windows XP SP-2 system with 512 MB DDR-1 RAM installed. Can I upgrade to Windows 7 with this amount of ram? This PC is for general purpose computing like net surfing, MS Office apps, VOIP chatting and maybe an occasional movie video. I am not inclined to upgrade the RAM since this is an old system and DDR-1 RAM is more expensive than DDR-2 RAM.
Prior to migrating to Windows 7 it would be best to run the Windows 7 Upgrade Advisor?
To determine if your current computer configuration will be compatible with Windows 7 please go to the following link: http://tinyurl.com/no4xb7
Another resource to verify compatibility is available at the Microsoft Windows 7 Compatibility Center located at the following link: http://bit.ly/1gW6Ns and can be used for both hardware and software concerns.
I installed Windows 7 on a system with 768MB of RAM and it worked OK, although it was just for testing and I never tried to run more than one thing at a time on it. I suspect that you could install Win7 with only 512MB of RAM but if you do anything remotely substantial (i.e., run a web browser and Office at the same time or open several tabbed windows in your web browser) then you'd be in for some pretty painful performance.
Jessica's advice to run the upgrade advisor is very sound. The biggest problem I had with my 768MB test system was that there were no drivers available for the video card. That meant running it in XGA mode which was painful in it's own way. If your system is of a vintage to have DDR1 memory then you might well be in the same boat.