This is a Windows 8.1 issue. I have not found a solution but this is a workaround.

I have done workstation installs from a mapped drive in Windows 8.1 without any problem.

However, when the issue that request a workstation install came up, I tried to reinstall a module from scratch and I couldn't see the mapped drive.

I have been able to recreate the issue in house with Adagio and with Dakota Toolkit installs. The issue still happens running the install program with Run as Administrator. It doesn't matter that the user is administrator of their own computer or Domain Administrator.

I had to map the network drives using a logon script using Run as Administrator. The same effect perhaps is achieved just mapping the drive using "the" administrator account.

I have been told that Net Use is not longer reliable with Windows 8. Group Policy mapping has not solved the problem.

In our case, we have a script that maps the drives every time we log in using Net Use. So, when I log off and login again, I am no longer able to see the mapped drives again with the installer.

If somebody has a permanent solution to this issue, please let us know.

Problem solved by changing registry entry:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System

EnableLUA should be 0

Disabling UAC is not enough in Window 8.