Media player and winrar real slow

ok, ill try to be precise and hope this is in the right category

i have a custom built pc i did about a yr ago
the specs are

msi k9n2 sli platinum board
amd phenom ll x4 940 quad core at 3.00
8gb ddr2
ati radeon hd 4770 graphic card
western digital 1tb hd-sata
seagate 500 gb hd-sata
western digital 500 gb hd-sata
sony dvdrw/with lightscribe
550 watt psu
windows 7 64 bit

my problem is that here recently i have been having issues with any media players and winrar
i have never had this issue until now and i am pretty good at trouble shooting all pc issues for the most part.

i have scanned my pc with..antivirus
avast/eset nod32/vipre

spyware
superantispyware/malwarebytes/spyware terminator

i have ran a hijackthis and i see nothing bad in there
all the scans come up clean

when i go to winrar and click extract or extract here i used to be able to extract a 700 mb movie lessthan a minute
now all of a sudden it takes about 3 or 4 minutes.
when i open a video file with any media player, my pc used to play them with no problems, but now there is lag and freezes until it gets going then it is usually ok.....

at first i thought it was logitech webcam software vid.exe but i uninstalled it and it worked fine for a few, but then it started acting up again.
if i open cntrol/alt/del there is nothing that takes up alot of cpu useage, everything is normal.....

i have went as far as taking everything from one hd and transfering it to another and using dban to wipe then and reformat them i reset all hd's back to zero and i still have the problem
i have used pc check to check all the drives/ram/cpu/motherboard and they all test ok..the test ran over night and took atleast 8 hrs to complete.

i have even wiped out my c drive that has windows installed and reinstalled a fresh copy after formnatting the hd and the problem still happens?

the only thing i have not tried yet is taking out ram and video card..i have all the latest updates from microsoft and ati

i have just installed the new release of avast free antivirus and scanned it with and it is clean

i only had 1 antivirus installed at 1 time...

is my video card going bad? would that affect winrar with its extraction time?
is a hd going bad? if so why is winrar and media players slow on all 3 hd's?
are they all 3 bad??