Windows 2000 startup problems

I have a Dell system running Win2K: 667Mhz, 128 MB of RAM, 9 gig hard drive. The problem is that it takes forever to startup, 5 minutes or longer and when Windows does load, the programs take long to execute. I have reinstalled, reformatted and reinstalled and defragment but the problem still persists. Is this a problem with startup files or is a device going bad?