.NET and RegAsm.exe

Hello all,

  Has anyone tried to register a COM dll with regasm.exe when deploying the library to other machines and get the "not a valid win32 application" error and find out that the RegAsm.exe file exists in the specific framework directory, but file size is 0 bytes? 


Just wondering if this is specific to our own workstation image or if this is normal.


As a side note is there a guide for choosing which .net framework to use?  The general idea is for the app/library to work on as many "standard" OS installs as possible.  I chose 4.0, most of the workstations are 64 bit windows 7 with a couple win10.  When I google different phrases for selecting or choosing .net framework I get all the guides for how to set up which one to compile to, but not the decision process of which to use.