You need more memory!

This by far is your biggest upgrade bank-for-your-buck. Check out this article. Speed Up Your PC from March 11, 2003

And this graph of performance vs. memory increase from the same article

Well, this is true if you have less than 512MB RAM and especially true if you only have 128MB RAM.

If your running Windows 9.x then you'll be alright with 96MB RAM or more.

If your computer is still 'slow as a dog' then there's a good chance you've got a parasite software infection.  Check out this overview of the parasite software problem.

Here are a few other things that can help speed up your computer.

• Defragmenting your hard drive
• Use NTFS for faster disk access
• Ensure DMA is set for your hard drives
• Eliminate Unnecessary Autoloading Programs and Utilities