I agree with the other posters in that your problem is you are trying to use a .NET application in WinPE.
WinPE does not include by design any .NET components, nor can it be included in a way which Microsoft supports (Sorry Pete, there isn't a package to add for .NET support). Developers have been haranguing Microsoft for YEARS on this score, but Redmond just won't budge.
People have gotten around this by,
- Coding in C++, VB6, Delphi, RealBasic etc etc
- Shoehorning in .NET into WinPE
- Using a special .NET binary compiler which creates your application as a standalone
- Try to do everything in an HTA
I've only ever gotten around this by using option (1). If you google around you'll see mixed success with (2). There is a paid-for compiler which will create a standalone package with the required .NET assemblies but I can't for the life of me recall just now the guy that made it.
Kind Regards,
Ian./
EDIT: After a good night's kip, I now remember the .NET assembly program that creates your .NET app as a standalone exe. It's the Salamander .NET linker.