Hi guys. I recently built a system and it has been running relatively smoothly for a while until all of a sudden my boot time at least doubled. I dont think that this is general slowing down due to more programs installed etc. there must be some kind of problem. At first i thought it might have been one of my USB devices so i removed all but my necessary ones (Mouse, keyboard, wireless network and sound.) and it was still very slow so im not quite sure what the problem is. Sometimes it pauses on the welcome screen and sometimes a black screen just before that. Any ideas on how to fix this problem? Also while im asking about this, does anyone have any tips on how to keep my PC running nice and smoothly? Normally i would just defrag/disk cleanup/virus scan when i start to notice it slowing down and physically clean the case if i notice any overheating.
I'll list my system and USB devices below.
Thanks
Intel Core i5 760 @ 2.8Ghz
Corsair XMS3 2x2GB 1600Mhz
ASRock P55 Deluxe
Palit GTX 460 1GB SE
750W XFX Pro
500GB Seagate Barracuda 7200rpm
Antec 902
500GB Toshiba External HDD
EMU 0202 USB 2.0 Audio Interface
Netgear WN111 Network Adapter (On a 2m USB A-B Cable)
Logitech K200 Keyboard
Logitech G500 Mouse
I'll list my system and USB devices below.
Thanks

Intel Core i5 760 @ 2.8Ghz
Corsair XMS3 2x2GB 1600Mhz
ASRock P55 Deluxe
Palit GTX 460 1GB SE
750W XFX Pro
500GB Seagate Barracuda 7200rpm
Antec 902
500GB Toshiba External HDD
EMU 0202 USB 2.0 Audio Interface
Netgear WN111 Network Adapter (On a 2m USB A-B Cable)
Logitech K200 Keyboard
Logitech G500 Mouse