If you change the board, you will need to repair or re install 7. If its a factory pc you will have to BUY windows 7, unless you have a retail version which you dont or you wouldnt have asked. Changing the cpu will not affect the operating system except to speed it up.
What If I have OEM version of windows 7 64 bit? And will repair install delete all my windows settings? Will repair install delete my files?
In other words, upgrading the cpu will be cheaper than buying a new board, if you have the option.
I'm not looking for a performance increase. I've got a problem with a sensor in my motherboard, making it register core temp as 255C. Which is insane and not true. But every time the sensor malfunctions, it throttles the CPU performance by like 90% to reduce what it thinks it 'heat'. I'm getting a replacement MOBO, but I don't want to have to delete all my crap and loose all my windows settings. =[