I want to start off by saying I've never done much inside my PC other than change a power supply and add a video card so this is all new to me. What I want to do is replace my old motherboard so I can use an i3 processor. Will I have to wipe my hard drive and buy a new copy of Windows or can I just make a quick swap?
Here's what I have:
OS: Windows 7 Home Premium 64-bit
Motherboard: ASUS P5QL-VM EPU
Processor: Intel Pentium E5400
Whether you will have to buy windows again depends on what type of license you have currently. If it's an oem license, then you'll have to get a new copy. If it's a retail license, then you can just simply swap or reinstall from your dvd.
To prevent issues, it's best to do a format and fresh install. I save my favorite websites on my internet service and start over. But you may get lucky and get some files to load. If windows doesn't give you blue screens, it may reboot 6-8 times before reconfiguring the new board drivers, but don't count on it. I recommend a bare bones test on a breadboard or the box the board came in. Remove the power supply if needed so the connectors reach the board. Use the onboard video to post. You can set the boot order, enable smartfan and calibrate the cpu fan, check your ram speed and voltage readings in the bios, save and exit. If your power supply is made for oem like dell or hp, replace it now. You can get by with an antec or corsair 400-500w unit for around $50 at newegg. Earthwatts is antec's better low end unit.