Vista - hard drive 100% useage SUPER DUPER LAG

hey my old computer is acting kinda werid its running on

vista 64 bit

750 sagate hard drive sata

750 psu

8500gt nvidia asus

some cheap asus mobo i think its the hp one bititatia or somthing

q6600 intel

4gigs ram


the problem is that my hard drive is always 100% useage the hard drive led light is always bold it doesnt even blink once and when i open any kinda program or even press start it lags like crazy and stops responding/ screen turns whte for like 2 mins each time i click on something

my comp was never like this before my ram and cpu never goes pass 50% useage anyone know how to fix this?

i turned off windows search and that flech thing and index
everythign is up to date im sure its not over heathing problmes cuz i have 5 120mm and 2 140mm fans in case and zalman 110mm heatskin
i was trying to provide a screen s hot of rescource montior but thats impossbile because once i click on the attachment or anything that pops up in the broswer the broswer crashes but i can say that the

responce time says 0-1500
read b/min is 0-9,000,000
write b/min is 0-16,000,000
this problem is really anoying because when the comp lags like this then i got to let my bro use my comp and he uses it like 23/7 T_T

"this problem isent all the time it comes and goes but it comes more then it goes"
ill say like 5 days out of 7 that this happens *_*


this comp has kaspersky anti viurs if that helps

I have a similar rig to yours and found that my HD activity light was on a lot as well. One way I managed to calm down the HD activity was to stop vista from making restore points, which has improved things (and recovered several GB in HD space). Failing that you could have system stability/virus issues? But one thing I would def. concider would be formatting the whole lot and going for a clean build and see if thats any different