I'm having problem to install ZfD 6.5 Server on NW 6.5.3

Original server SH01 (NW 5.1.6) is migrated to new HW.
After migration the new server has the same name and IP address as the original server (SH01).
The orginal server had ZfD 4.01 installed.
As a result of this e-dir contains several ZEN 4 objects.

During migration the original volumename SYS1 was replaced with the name VOL1.

When installing ZfD 6.5 I select server SH01 and then both Desktop Management Database and Inventory Database are preselected and can not be unchecked.

The next step in the ZfD installation is the File Installation Location, and here is my problem.
Server SH01 is selected and in the right pane is volume SYS1:\ preselected and greyed out
so I can't change it to the correct volumename VOL1.

The installation documentation says that if a previous installation of ZEN 6.5 WS Inventory or Remote Mgmt.
is detected the existing path is displayed and dimmed.

Since I don't have a previous installation of ZEN 6.5 but a previous install of ZEN 4.01 I suspect that the
installation program finds the old path (SYS1:) somewhere in e-Directory.

How can I correct this problem ?

L-G Nihlman