How to know the target platform of an .Net assembly

If you want to know about dll in which platform will run.
I am assuming your assembly has available in GAC
Open GAC folder
How to open GAC folder.
Click start
Click run
Type: assembly
Now it will open GAC folder
Or: C:\Windows\assembly
This is the path of GAC
Now in the GAC folder, you can see all dlls
Select any dll, you will windows propert: Processor Architecture
If it is x86 mean it will run in 32 bit environment
If it is x64 mean it will run in 64 bit system
If it is MSIL, it will run in both 32 and 64 systems (Any CPU).