have you scanned for spyware? do you have any AV's running?

I have disabled all spyware,and have adware6.0 on my system. Not sure what you mean by AV running.

* Exactly which OS are you running?
* Are your hard drives set to power down after a time (in BIOS or Windows settings)?
* Are your IDE DMA settings correct in the BIOS?
* Is your hard drive encrypted?
* Have you run a virus and spyware scan? If so, are your data files current?
* Are you running AC '97 on-board sound? This can sometimes cause lagging due to interrupt/IRQ switching (admittedly, rarely--but I have seen it). A decent PCI sound card helps here.
* Go into the BIOS and turn S.M.A.R.T. on, then download a free utility like HDD Health from http://www.panterasoft.com to test the hard drive (there are others, as well).

S.M.A.R.T. is a self-monitor feature built into current hard drives. It can report hardware problems, including impending failure. There is some system overhead involved, which is why it is turned off by default--but it is useful in a case like this.

I am running Xp. Harddrives run all the time i think. All settings are set to what they are suppose to be. I run virus and spyware scans all the time, and are current.And i have AC97 but think i am running sound blaster 5.1.

Another possible diagnostic technique would be to use something like TinyResMeter or CPUCool (find using Google) to monitor CPU usage. You could also play an MP3 music file in the background to see if there's a glitch during the lag time. If the CPU usage meter goes to 100% (or close) or the MP3 playback breaks up, those are clues.