Skyrim keeps minimizing on my PC?

I just bough skyrim in the steam sale, first time i played it, it was fine, the next day when i played it again it keeps on minimizing every 10 seconds. I have done nothing to my computer since. My computer has fairly decent specs so i don't think it is that, (cpu: intel core i5 4670, 8gb ram, graphics card: xfx Radeon HD 7970). Any suggestions?