Boot difficulties

Hi. I'm having some issues with starting up my pc, although I'm not entirely sure if it's a hardware or windows issue. Maybe anything of the following sounds familiar.

Normally the pc runs fine. When I turn it off for a few hours, it doesn't boot properly afterwards. The first time I start it, I hear a loud mechanical noise (like an engine or helicopter) that seems to be coming from an area around my hard drives and front fan or the gpu (it's really hard to figure out where exactly, I tried). Restarting the pc a few times gets rid of the noise.

The pc usually hangs on the BIOS screen, until I restart it a few times. This time it took a while…

A few more details that may be relevant:

• I downloaded a program from Western Digital to check my hard drive, it passes the check. I had a drive fail before, and I don't hear the usual clicking noise that accompanies it, but I don't rule this out completely.
• I haven't reinstalled windows for at least two years, that probably causes all sorts of problems
• I was rarely turning off this pc, it was practically running non-stop for the last 4 years

I'm just wondering if this pc can survive until summer. Right now I don't have the time to reinstall everything or juggle hard drives. The current plan is to keep it on as much as possible, and hope it can start again whenever I have to shut it down

System specs:

cpu: Intel Q6600 (2.40GHz)
mobo: IP35PRO

gpu: AMD Radeon HD6800
ram: TeamGroup Ram 2GB Kit DDR2 800 4-4-4-10
		 A second random kit of 2GB, both in dual channel

main hd: WD 150 GB Raptor-X
storage hd: WD 1TB Blue Caviar

DVD-RW

psu: Seasonic 650W S12-650 ''Energy +''

Windows XP SP3

Sounds like your video-card fan might be on the way out, as they are (mostly) poor quality with lousy bearings. If you have on-board video you could try disconnecting your video-card or trying another one if available to see if that noise goes away. The noise could also be one of your case fans so if not the video-card fan, temporally disconnect them to try and isolate the noise.

For the hanging problem, firstly do a OS cleanup by running your Disk Cleanup and then defrag. if it hasn't been done in awhile.

Run SFC /Scannow to check your windows files integrity.

note: Sfc /scannow will inspect all of the important Windows files on your computer, including Windows DLL files. If System File Checker finds an issue with any of these protected files, it will replace them.

Have your Windows XP installation CD handy.

Go to Start, then to Run, and type in SFC.EXE /SCANNOW (note the space between the SFC.EXE and the /SCANNOW). Then press Enter.

The program will ask you to insert your Windows XP installation CD if any files need to be replaced.
If asked for your XP CD, visit Windows Update after the scan is completed (Please note that there won't be any confirmation dialog - the program will just exit).

If these step have no effect on your PC's current performance, other troubleshooting procedures are required.

Thanks for the reply. I tried these steps, but I'll probably need to repeat some of them for a few days to make sure the results are consistent (the nature of the problem makes it hard to tell whether it's solved because I disconnected the fan or because I restarted the pc). I also tried replacing the video-card with an older one, but it was making so much noise itself that it's probably pointless. I ran the Disc Cleanup and defrag, not sure if it had an effect yet. I typically run defrag rather often, though there are several game files that refuse to be defragmented. Seems that SFC /Scannow requires the Professional windows version, I own only Home. It displayed a progress bar which I let run to the end, but it didn't accept the Home CD when it did ask for one.

Normally the pc runs fine. When I turn it off for a few hours, it doesn't boot properly afterwards.

to me this sounds more like a failing power supply or bad capacitors on the motherboard, had the same exact problem with my daughters pc, runs fine when it finally is able to boot but because of bad psu it struggled to provide enough power for the initial startup process,
the loud fan just on startup is more a normal thing i'd associate with a graphics card's first power up, some spin at max speed until the drivers are loaded then it spins down again to a speed that keeps it cool without being excessively fast/noisy (could definitely be on the way out tho like lee said.).

I was rarely turning off this pc, it was practically running non-stop for the last 4 years

If your a gamer (like me) the hard-drive, video-card, case fans and PSU (if it's not up to the task), all have a hard time, so I'm not a big fanboy of the 24/7 argument. Hardware is far more robust than it used to be, so when not in use I let things rest.

With boot-up problems but working OK after slow boot, It might be a good idea to leave the computer on if you only need it to last until summer and you don't want to start replacing things because you plan to build or buy a new computer at that time.
What you might do though is a freshen-up of your OS using the XP home disk you have, as the fact that SFC Scannow asked for a disk means everything is not right with your OS files. After 2yrs this can happen for sure, especially if you have been using reg. cleaners or Optimizers after software or game un-installs. See How to Reformat and Reinstall your Operating System.

Terry might be onto something about the PSU, motherboard capacitors and spinning-up noise (aluminum and gaming cases for sure) can sound pretty loud, but not if the computer has just recently started making it. If the sound is new and it's been getting increasing noisy, I'm guessing worn fans, especially if the computer has been on 24/7. Is the PSU a quality item or a cheapy that came with the case?

Games are really increasing in size and the last couple I installed, Assassins Creed and Mass Effect 3 were both around 15GB and standard Windows defragers just aren't up to it after installing these game sizes. This freebie Ozlogics will quickly bulldoze its way through the largest file fragments.

Cheers,
Lee