Ok so Im planning on installing the OEM version of Windows 7 Ulitmate on my system but I have one question. From what I have read you can "Only use the disk once" meaning for one install on one system. Does this mean that if at a later date I wanted to do a clean install on the same system it would NOT work?
You may re-install a OEM version on the same computer and reactivate it with no problem. If you change some components, you may have to call microsoft, but when on the same computer - it's just a formality.
There is no limit to thee number of times you can reinstall on the same computer and hardware, so long as you don't reinstall more then about 3 times in a 6 months period it will reactivate on line. Too many reinstalations and activations in a short space of time will require a phone call to Microsoft to get it reactivated.
I have done a dozen reinstalls of XP when trying to diagnose a driver issue w/o MS giving me headaches. Dunno if Win7 follows suit. Again, w/ XP, you had to change 6 things before activation became an issue.