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#830
Would that cause me any problems?
No, you shouldn't have a problem doing that if you wanted to dual boot them. If you just wanted Windows 7, then a clean install is always best.
If you have another monitor and graphics card you can test using them one at a time instead to see if you may have some sort of hardware issue with your current ones.
It wouldn't hurt to flash your BIOS with a newer version (if available) to make sure that is not corrupted.