[Vivek788]

as an update to the probs...as a last resort,last week i installed ubuntu.All probs seemed to have vanished.I was able to connect the 120gb along with the 250 gb.I even copied complete data and formatted the 120gb to one partition using partition magic.
Then after restarting,Windows has never again booted up.A blue screen flashes and system restarts.Ubuntu works fine.I perfomed memory check and also cleaned the RAM...no use.

Also my friend who took my 120gb to backup his data suffered the same.After copying and restarting,he had to reinstall windows and his ubuntu.Lot of data loss was caused.What cud be the prob with my hard disk?It is quite new ....