My PC (Windows Vista) was working perfectly fine until this morning. When i start it, the boot screen (with the option to press Delete to enter setup and F12 to open boot menu, etc) appears for 5 minutes (normally remains on screen for 30 seconds or less) and the HD light flashes for about 30 seconds, then shuts off. When it finally starts to load windows, the screen goes black for 10-15 more minutes, then I finally get the normal windows loading screen and it runs normally.
It usually takes about 3 minutes for the entire start-up process.
I've run sever virus scans, I've run CCleaner and I've trued starting it in safe mode. It took about 10 minutes in total to start in safe mode which is still slower than usual.
I ran out of software ideas so i stripped it all down and inspected each part visually. Found nothing wrong. When i reassembled it, it was working find for 3 or 4 start-ups and then went back to the 20 minute ordeal.
I have a feeling its a hardware problem (either mobo or HD) but I'm no expert so any help or advise would be greatly appreciated.
Here's a list of my hardware:
Processor: AMD Athlon 64 Dual core 4000+ 2.1 GHz
Motherboard: Acer F690GVM
Ram: 2Gb DDR2 Single channel
Hard Drive: Barracuda 7200.10 SATA 3Gb/s 320Gb
Graphics Card: Diamond ATI Radeon 4670
PSU: Apevia 680W Iceberg
I'm fairly new to this so please try to explain in detail if possible. Thank you for your help