Error 1327: Invalid Drive C:\

Should be fairly easy process.

Hit WinLogo and type 'regedit'

Open the following key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
In the right pane select 'ProgramFilesDir' which has default path set to 'C:\Program Files'
Change this path to 'E:\Program Files'
Close registry editor and try to run installer again.

You may also try setting up a share of a folder on your E: drive, possibly the program files folder, then use a net use command- such as net use c: \\computername\sharename. This would use the c drive letter and point iit to the shared folder you setup. once your program is installed you may be able to get rid of the mapped drive letter if you can run the program directly from the E:\. If you need to leave the C drive mapped for whatever reason, you can use a /persistance:yes in the command so it remaps everytime the server reboots.

Thank you.. I contacted the developer of the custom program. What happened is I think they hard coded the path where they want the MSI package to look at for the C: thinking no one will have there system drives as a different letter which is a stupid move. What I had to do is resize and create a new partition and assign drive letter C: to it then it was able to work. I wonder why they did that in the first place. They suggested reassigning the system drive which will mess up the dependence on the E: drive.