Since moving to Visual Studio 2010 on Windows 7 x64, I’ve been getting this error a lot. Every time I open Visual Studio by opening a file rather than running its executable directly, in fact.
Most of the answers seem to revolve around running Visual Studio as a normal user rather than an administrator, but I was already doing that.
Eventually, a reply to this bug provided an answer.
When I checked the key, I saw
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\DDECache\VisualStudio.10.0\system] "ProcessName"="devenv.exe" "WindowName"="Visual Studio Application Management Window" "WindowClassName"="VisualStudioAppManagement"
Deleting the “system” key then opening a file again worked and replaced the key with working values
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\DDECache\VisualStudio.10.0\system] "ProcessName"="devenv.exe" "WindowName"="DDEHandler" "WindowClassName"="DDEHandler"
When it has the correct values (refresh to make sure that it does) remove “set” permissions from your own user so that it can’t replace them with the bad values, to make the change permanent.