I just downloaded and installed windows 7 onto an old maxtor hard drive (from my grandpa's old pc). It is a 5400 RPM IDE so it is pretty slow to begin with, however it seemed fine under windows 7. I installed firefox and soon after, my HD started making a wierd slow clicking noise whenever it was working. Everything involving the hard drive has now slowed to a crawl. Is this a fault of windows 7, firefox in windows 7, or is it just my HD's time to die? (keep in mind it is almost 10 years old)

It seems problem related to your HDD and its just to die...( can't say )