buy it from
Overclockers UK Chips, and help support me in my new job, not MicroDirect, they're rubbish
don't buy second user stuff unless you really have to, 'tis false economy, hdds are so cheap now anyway. You will find them increasingly SATA though, which is no use if you''re kitted up for IDE only, unless you get a SATA adaptor.
Celerons, well my little spawn boy has a 1.7ghz Celeron in his, and with a reasonable graphics card, they're really not as bad as you think. You'll struggle with it in 6 months time though, but you can get a 2.6 or 2.8 celeron for very few notes, providing your mobo supports it.
as far as your problem is concerned, yes it is prob your hdd, after a while spindles and drive electronics (which is what IDE means) begin to go, often due to heat. it could be the IDE controller on the mobo but I'll bet onthe hdd. Replace it now. And take a backup now, or you'll be saying bye-bye to all your hard work. Ed will confirm that when I say "do a backup now" it's prob a really good idea to do a backup now.
I recommend Seagate Barracuda & WD Raptors for speed and relaiabilty. All drives in my main pc and my server are now Seagate 80gb. Maxtors are blazingly fast, but get hot and the spindles die. also they have a weird electronic problem if they get too hot, and have poor em shielding - I've thrown loads of Maxtors away, but never one of the new Seagates (yet) everything else, Fujitsu, Samsung etc are just cheap cr*p now imo. IBM/Hitachi aren't bad, but for what they cost you can get a Seagate and be like Uncle Taw. dont get an IBM/Deskstar though, they're not called "Death Stars" for nothing.
of course if you're really stuck you can beg me to show pity on you and provide emergency upgrade supplies, but you will have to grovel bigtime and owe me stacks of favours in return! However my goodwill is easily bought with Resse's Golden Cups.