Windows 7 Professional should work on most computers that used Windows XP. You need, at least, 4 Gigabyte of memory, and 200 Gigabyte of Hard drive space. Your CPU (Central Processing Unit) or your microchip should be at least a Dual Core CPU. You will have to go to the Microsoft Website to compare your computer to the Windows 7 Professional Hardware requirement. If you really need an Operating System that will work on almost any computer, I would suggest that you use Linux Operating System. This can either be an Ubantu Linux or a Debian Linux. This is your last chance to use this Windows 7 Professional. Microsoft will no longer support Windows 7. All I can say is that Windows 7 is now affordable to buy and there are many software that you can use for about 3 more years. Good Luck!