Re-installing windows help!

[Bradley99]

Hello, The other day my motherboard died, nothing displayed on the monitor the PC crashes and the USB ports do not work. I am going to order a new motherboard in a few days and because the PC came with windows installed I need a new copy of windows. The only thing I managed to back up was my passwords as it was sudden (I went to bed left my PC on, woke up and it was in the BIOS trying to boot of my USB  stick. I changed it to HDD and it wouldn't display anything and broke) So if I was to get windows 8 instead will it be ok? because my HDD has windows 7 on it but like it said its a OEM copy and only works with my busted motherboard so I need tips on wiping the HD and how to install windows 8 to a clean drive and my new motherboard. 

 

OLD MOTHERBOARD: http://www.foxconnchannel.com/ProductDetail.aspx?T=motherboard&U=en-us0000554

 

NEW MOTHERBOARD: http://www.overclockers.co.uk/showproduct.php?prodid=MB-450-GI&groupid=701&catid=5&subcat=1965

 

The windows I plan to get: http://www.overclockers.co.uk/showproduct.php?prodid=SW-152-MS&groupid=33&catid=1555

 

Let me know how to go about these stressful installs and problems and another question will I need to buy some new thermal paste or can I use my old one on the CPU and Fan?