I can't able to access our server local drive through network within 20-30 min. After this situation i must restart the server. I have alredy check the virus enfection, windows updation.Server is HP-Proliant DL360 & Windows 2003 std edition.

Any error log in HP SIM or in event viewer related to Hard disk drive..

No hard disk related error, This error is in application.Faulting application svchost.exe, version 5.2.3790.3959, faulting module shell32.dll, version 6.0.3790.3959, fault address 0x00071ef1.

It looks like that this article may help you: http://support.microsoft.com/Default.aspx?scid=kb%3ben-us%3b958644&x=19&y=4 There is nothing about particular module shell32.dll , but I still beleive that it is a vulnerabily issue. Try performing recommendations from the article.

How often you need to perform these action like reboot the server to access the drives..

Yes but this true, tell me do u have any solution for that it's urgent.

you can try running a offline hardware diagonastic in order to check any hardware issue with HDD..