Solved Reinstalling Win7, error code 0x0000007E

[gregrocker]

If you have XP or Vista qualifying for using Upgrade version, then you can insert the key after doing the quick registry workaround Option 3 in Clean Install with a Upgrade Windows 7 Version

 

[joeevans1993]

I don't have xp or Vista, I went straight to 7 on my desktop!

 

[gregrocker]

Then since you're a builder you may want to get another OEM. It's a shame you didn't save the Product Key as one would property worth $100+ which you own for life.