Windows 7 not compatible with multiple websites.

I am new to this so bear with me. I am running Windows 7 (64bit, Home Premium) and IE8 (new Acer PC in April '11). I am having compatability problems with sites I originally was able to access (not able to log on). Also, having moved from New England to SC, my wife and I would like to join Facebook to keep in touch with family. When I access the Facebook web page I am getting a message that I need to update my browser. I have tried IE9, Chrome, Navigator & Safari and continue to get the same response from Facebook. I have the same issue with other sites I was able to access previously (I recall reading somewhere that in June some of the "patch tuesday" fixes from MS might be troublsome). Short of a Windows 7 re-install does anyone have any suggestions?

Reset IE8: Tools/Internet Options/Advanced/Reset
Command Prompt: sfc/ scannow

Thanks for the input - I disabled IE9 in "Windows Features" and then uninstalled it via the "Installed Updates" route as MS recommends. I then re-enabled IE8, restarted and reset as you recommended however, the problem is still there. I have not checked if system restore is active and whether there is a restore point I can pick up back when everything seemed to work ok but if there is a restore point is this something I should try?

DeadDog said:

...if there is a restore point is this something I should try?

Sure. But after doing it don't forget to go back to Windows Update to get the updates you need. You can still postpone (uncheck) IE9 since that is not a needed security update.

I'll give it a try sometime today and follow up.....