Re Enable System Restore

System Restore which is a good feature in Windows to revert our system to some earlier better state when the system was working fine, shows up many problems.
sometimes we got problem that his System Restore has been disabled may be due to some Virus activity or due to some changes made by software
How solve this problem and enable the System Restore again?
here this step

1. Click Start, Run and type regedit.exe and press Enter

2. Navigate to the following key:

HKEY_LOCAL_MACHINE \ Software \ Policies \ Microsoft \ Windows NT \ SystemRestore

In the right-pane:
Delete the value DisableConfig
Delete the value DisableSR

3. Exit the Registry Editor.

In Windows XP Professional, you can accomplish the above using Group Policy Editor as well.

1. Click Start, Run and type GPEDIT.MSC

2. Navigate to this path:

-> Computer Configuration
--> Administrative Templates
---> System
----> System Restore

3. Set Turn off System Restore to Not Configured

4. Set Turn off Configuration to Not Configured

Refresh your desktop (press F5)then The System Restore feature will be enabled again