Vista won't load in normal mode,but loads in safe mode

[astig129]

Hey guys I need help,My computer won't load my OS. It goes to the windows vista loading screen ,just before the welcome screen and accounts.The vista loading screen is stuck there.Before this I got a blue screen and my computer restarted but it didn't get past the loading screen,What could be the problem? Prior to this I was installing a Disk drive in it.and cleaning the processor fans and gpu fans with a toothbrush,But I was gentle and didn't really touch the pcb of gpu that much. Safe mode oddly enough works just fine.So what could be the problem? Is it a software or a hardware issue?

 

[hang-the-9]

Could be either one. Get a new hard-drive and install a clean Windows setup on that, if that works fine, it's software.