ZEN imaging install

Having issue with upgrade from version 4 to 7. In the installation log,
I get the following message: Imaging components failed to install to
<server name> on E: Rest of ZEN components at this point are functional,
however, imaging console still says version 4. During this install, I
didn't have a drive mapped to E: (sys volume) I then mapped a drive (E)
to sys, performed another install of just imaging and now the log says:
Imaging components failed to install to <server name> on G:

I also had a drive mapped to F: which was my mapping to vol1. Any ideas
why the install is choosing it's own drive letter?