Sometimes when you go to install or reinstall client access services or owa running exchange 2007 or exchange 2010 the original installation did not assign the correct version of .net to IIS (such as 32 bit instead of 64bit.)
To resolve this issue proceed as follows.
- Open Command Prompt.
- Change directory as follows:
- For 32-bit machines change to:
- For 64-bit machines change to: