I also had the same problem. I tried replacing the blocked CompMgmtLauncher.exe with a known working CompMgmtLauncher.exe file from another win 7 x64 system, and still nothing would happen.
I discovered that a third party shell extension was causing the problem. In fact, I have installed a security product "a-squared Anti-Malware 4.5" (http://www.emsisoft.com/en/software/antimalware/ ), on the computer with malfunctioning right-click context menu, that would not execute CompMgmtLauncher.exe, and hence would not start CompMgmt.msc.I solved the issue by removing the a-squared context menu option, as follows:
Open a-squared Anti-Malware, click Configuration , and uncheck Activate Explorer integration. The trade-off of this option is that you won't be able to scan individual files/folders from the context menu (if you really do need that functionality, it's easy to recheck the box and re-activate explorer integration).
Now, I can right click my computer and "manage" works like a charm.
Reference: http://social.technet.microsoft.com/Forums/en/w7itproui/thread/70897346-38b3-4872-99ec-8e1c701fc7dc