I have been noticing for years the presence of two strange files in the file system of my computers:

• pidpropsca.dll in C:
• pidca.dll in C:\Program Files

Finally I decided today to investigate what they are, where they came from and more importantly, if I can delete them.

I thought it would be easy searching on the web. But both Google and Bing returned an incredible small list of results, and none of them was useful. The Pidpropsca.dll doesn’t have copyright but the other one, pidca.dll, belongs to Microsoft, and they were created in 2005 and 2006. No many clues here.

Then I used the Dependency Walker (depends.exe) utility to inspect the functions exported by those dlls. I found something more interesting:

• pidca.dll exports the functions ValidateProductID and DllMain
• pidpropsca.dll exports the functions SetAcademicProps and SetPidProps

It was the latter the one that gave me the clue, because “Academic” is something that Microsoft Visual Studio uses as one of the SKUs for editions. Also, I learned some days ago that to go from the Visual Studio 2010 Trial Edition that I got from Microsoft some days ago to the RTM release that was published on MSDN Subscriber Downloads some days later you need a “pid”,  which I guess it means “Product ID”. So, the dlls came from some Visual Studio version. I started searching the setups of all Visual Studio versions and I was lucky enough to find them at the fist version that I tried: the Visual Studio 2005 Team Edition for Database Professionals. This team edition came as a separate product after Visual Studio 2005, which originally only offered Team Edition for Developers, for Architects or for Testers, and the unified Team Suite. The setup folders of Visual Studio 2005 Team Edition for Database Professionals contain those two dlls.

I found later from this post of Quan To that “ca” stands for Crypto API and that during the installation of Visual Studio some data needs to be encrypted. Somehow the Visual Studio 2005 Team Suite and the Visual Studio 2008 Team Suite (which includes the Team Edition for Database Professionals) do all that stuff without using or leaving those two dlls in the file system. But Visual Studio 2005 Team Edition for Database Professionals uses and leaves them and since it was a separate product that I guess not many developers installed (I did because my MZ-Tools add-in supports it for some features), it is no surprise that there aren’t many search results on the web about those dlls.