i did these steps and BINGO!!!! it has solved all my problems and now everything is fine..windows is activated and slmgr scripts working fine now
1. On the Desktop, right-click My Computer, and then click Manage.
2. Under ;Services and Applications; click Services, and then stop the Windows
Management Instrumentation service.
3. Delete all of the files located in c:/windows/System32/Wbem/Repository
folder.
4. Restart the computer. The files are recreated when the computer restarts.
this steps can be used for troubleshooting:
1.cmd syteminfo:not found error or if system info is not available under pc info section.
2.local WMI provider could not be contacted error or issues related with WMI files curreption.
3.some of the windows activation errors!! must try