Manoj, you probably fixed it by now. I had the exact same issue right now (only "Open Devices and Printers" showed up. What worked for me was the sfc /scannow, as Brink pointed to.
Below a printout of running that command:
Beginning system scan. This process will take some time.
Beginning verification phase of system scan.
Verification 100% complete.
Windows Resource Protection found corrupt files and successfully repaired
them. Details are included in the CBS.Log windir\Logs\CBS\CBS.log. For
I didn't bother looking at the details in CBS.log, but those might hold the answer.
thanks Brink! and thanks manoj for posting so detailed making it easy to search for this resolution.