How to programmatically check GAC for an assembly?
From .NET, the reflection API - Assembly.Load(...) will throw a FileNotFoundException if it does not find the assembly. The API requires a fully qualified assembly name, so I assume it must be in the GAC. I am using it to test for the presence of SQL Server Compact Edition:
Assembly foo = Assembly.Load("System.Data.SqlServerCe, Version=3.5.1.0, " +
"Culture=neutral, PublicKeyToken=89845dcd8080cc91");