I know it's not recommended, but how do I increase the processor speed on my computer? What's percentage increase is too high?

http://www.computing.net/cpus/wwwboard/wwwboard.html

Overclocking can be hazardous to your PC's health, especially to someone who is inexperienced. The speed increase is normally pretty small and not noticeable under normal usuage. Most overclockers just do it for kicks. Do yourself a favor BACKUP!

The answer depends on the computer in question. While I may not agree 100% with ham30's response from above, I do not disagree with the part that emphasizes the importance of knowing what you are doing before attempting to overclock anything. Now to answer your inquiry, the likelyhood of getting any beneficial result from such an exercise with a Compaq is very very slim, because to begin with, your OEM PC comes with a crippled BIOS. Now you can try to do it from within Windows using programs like Speedfan, CpuFSB, SoftFSB and the rest, but it is not the prefered nor most efficient ways of overclocking processors. The verdict therefore is to start looking at buying a newer and much faster PC, if you're doing stuff that requires more performance than your current system can deliver.