1.) The latest revision of the Windows OEM licensing terms prohibit the purchase for and installation on your own personal computer. The OEM license is now limited to purchase by a system builder for installation on a newly built computer being sold to a this party.
2.) You may need to completely wipe the hard drive with a program such as DBAN if the issue is related to system files remaining from the failed installation. (The exact error message is preferred.)
I have an Acer, Aspire, T-136 previously running xp. Purchased new win 7 64 bit OEM program. I tried to do a clean install on a formatted HDD. Win 7 loaded up to the point of entering the product key when the system shut down from a hardware failure. After repairing the hardware there was no operating system on the pc. I attempted to install the win 7 program again and the install fails with a message that the program was installed once and will not install again?
Help!! I spent hours trying to contact Microsoft with no luck. All their help lines are automatted and their menus irrelevant to my problem.