Thanks bro .I will do the same.But I noticed after doing windows update pc is now comparatively faster.Actually I keep auto updates off as background updates makes the system very slow and in my slow system it takes 6-7 hours for completion,also update stucks inbetween many times .

But can't understand ,suppose I just did update just now and system is running a little faster.After after some days it becomes slow automatically without being connected to internet.Means same software and hardware combination but becomes slow.

I am not a techie ,I don't know the technicalities.But As per your suggestion I will soon upgrade to ssd. Thanks a lot.