I tried to install IE7 RC1 over Beta3, of course if you have a custom sound scheme and try to uninstall Beta3, it fecks up explorer and most of windows. I was laughed at on the M$ support forum for not knowing (***, it says it nowhere!) and i spent 2 hours getting my PC back working. I have a mix between IE6 and IE7 RC1 files, and it doesn't work at all.
Firefox/Safari work fine though
Don't think the "autoupdate" works in anything other than IE though does it?