PC freezing for sometime after boot-up!!!

[jerrin_ss5]

I use a windows 7 ultimate 32-bit OS, after it boots and i begin my normal operation say like browsing for example and suddenly my PC does'nt react for some time although i can move my mouse pointer and click to minimize.After some time my PC returns to normal state and does everything at an instant say suppose during the freeze time i had clicked on Ccleaner,called up task manager and clicked on my computer , all of them happens to come up at the same time.I had a doubt with regarding to my RAM as it has timings of 5-5-5-13. Would such timing cause such a state of freeze to happen after booting.i did not overclock any components and all the components are running at default speed. I happen to observe this phenomenon in Windows Xp also though not in ubuntu.Also i removed all the dust covering heatsink and fans. All the start-up programs are kept to bare minimum.Please help.
My processor temp - 41-46C
Graphics card temp - 56-75C
My configuration:-
Processor -- AMD Phenom-2 X4-810
MO-BO -- Zotac 8200 A-E
RAM -- OCZ PC2 6400 -2GB
OCZ PC2 6400 -1GB
HDD -- Segate 250GB
WD green 500GB
RAID 0 config.
Graphics card -ZOTAC GTX 275 amp edition.
Power supply - TAG 750 watts

[Tron91]

have you gave a thought on the antivirus you using at present? sometimes antivirus can do this sort of weird stuff?

also you could be having the same situation as mine. my comp does the same and i know the reason for it. i have two hard disks and i have selected Power Save mode in the power settings which sometimes switches off my second HD if it remains idle for more than 15 mins.

[jerrin_ss5]

Well i use AVG now but have been using kaspersky trial version before!!
Also after turning off my HDD switch off feature the time interval for freezing as reduced considerably but still seems to exists!!
But thanks for pointing out that it sure helped !!