Ok my error was caused by another piece of software overwriting the value in the R_SHLIB_LIBRARY_PATH environment variable.
Steps to fix:
1. Uninstall IDT
2. Locate the R_SHLIB_LIBRARY_PATH environment variable under my computer properties.
3. Set the path value to your SAP install directory such as C:\Program Files\SAP BusinessObjects\
4. Re-install your client software
Note that if you don't change the variable before you try to install you will get a message explaining the issue.