If you installed Microsoft App-V Management Pack and are wondering why System Center Operations Manager 2007 has failed to detect and to monitor these servers as App-V Servers, then it may be because you've installed App-V 4.5 on an x64 system. This's due to App-V 4.5 server is a 32-bit app, and so writes its information to 32-bit area of registry. On an 64-bit machine, this means it writes information to HKLM\SOFTWARE\Wow6432Node\Microsoft\SoftGrid\4.5 area of registry, rather than HKLM\SOFTWARE\Microsoft\SoftGrid\4.5. This's a potential problem because OpsMgr uses App-V registry keys to decide if a machine is indeed an App-V server. Since OpsMgr agent on an x64 server is a 64-bit program, it'll look in standard registry location for App-V registry keys," explains Mirosoft.
To work-around, you should copy HKLM\SOFTWARE\Wow6432Node\Microsoft\SoftGrid\4.5 registry keys to HKLM\SOFTWARE\Microsoft\SoftGrid\4.5 registry area so that the OpsMgr Agent will be able to find them.