I have the Teklynx LabelView DLL in use in my application.
To use the DLL, the product must be installed on the PC, and I have to have the DLL in my project so that my code can access it.
My product is installed on my Development PC, also. Occasionally, I will uninstall it after trying a version.
Anytime my product is uninstalled, the LabelView application becomes unregistered on the system. I have set the DLLs as SharedLegasyFile and Permanent in the VS Deployment project, yet immediately after removing my application, I can try to rebuild my VS2010 project and get undefined item errors.
To fix it, all I have to do is open the LabelView program, close it again, and my VS program will compile with no issues.
I don't know why, but I know it works.
I don't know if ctacke's OpenNETCF package has an interface that you can use to open it so that it can re-register itself, though.