There is an old burt about the same problem. http://web.netapp.com/~burt/views/341/341621.html
Looks like this installation curruption may happen when you upgrade from an old version to a new version and uninstallation of the old one didn't go fine in the upgrade process.
Fix to fix this as adai said.
1. Un-intall the current NMC.
2. Delete all directories from C:\Program Files\Netapp\Management Console or where ever you have installed your NMC.
3. Re-install and it should work alright.
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