I am using a local PSU (450W). My doubt is also for the PSU. what should I do for the cure of high temp. Can frequent abnormal restart cause hard disk crash?
Sorry for the delay in response...
You have to determine if you have high temps first by running a program such as HWMonitor and document the temps. If they are hot, you can look at add additional fans to your case, clean the case (dust cases heat), add an aftermarket heat sink to the CPU... etc.
Abnormal restarts shouldn't damage your hard drive, as long as they are adnormal... If you are restarting every 30 hour for example, it could start to put a little wear on the hard drive. I would run a disk scan check on your hard drive to see if there are any errors or check your S.M.A.R.T status if you have the ability to.