Just built my new system right before the new year was rung in. I have a Z97 Gigabyte motherboard with Devils Canyon Core I5 processor at 3.5 Ghz and Ripjaws 16 Gigs of Ram. I am still using my old power supply, case, hard drive and graphics card with a new Blue Ray DVD burner. I didn't have to re-install Windows 8 after the new build, but I was hit up by Microsoft to re-establish that I was still using my win 8 copy on one PC. I was also hit up this morning by my copy of Office 2007 to reactivate it with my new hardware. Last night, even though I had the internal LAN configured within the BIOS, the LAN wouldn't work until I loaded network drivers for the motherboard. I have never had to load network drivers before. Each motherboard is configured differently.
I recomend a complete reinstall. That includes to delete all partitions on the primary HDD. Despite my years old 500 GB HDD and old hardware basing on the ancient but still powerful Core 2 Quad Q6600, Windows 8 starts within seconds and runs like crazy.
Weren't you the one, who told me that I didn't have to re-install Windows 8? If so, you were right. I backed up everything in anticipation of doing it, but now, I will just see how everything works.
Recently, I was having trouble with my Cyberlink PowerDVD Ultra 13, showing an error message every time I tried to play a movie. I traced it back to the NVIDIA drivers. Even though, I had installed the latest driver, all the old drivers still remained, even though they weren't visible. When I removed all the old drivers. Cyberlink played flawlessly, but that was only after I restarted the system. If I came in on a cold boot, I still got the same errors, both for Cyberlink and Geforce Experience. Now, since I have installed the new motherboard and I5 processor, everything works perfectly, even with a cold boot. I would say that maybe my motherboard or Q9400 processor were causing all the issues. I figure the board or CPU was getting ready for catastrophic failure.