Now this is weird.....

I have a brand-spanking new server machine to configure with all
sorts of RAID goodness, but before installing anything I figured it
would be smart to to a dry run of what what was intended within a
VMware machine running XP pro.

I have a nice clean XP VM that I can clone as my test bed.

Problem is, this VM doesn't have enough disk for the db tests that I
want to run. So I created a new virtual disk and used the regular
windows tools to mount it in an empty NTFS directory called
c:\database.

I then tried to install FB2.1 into c:\database\firebird_2_1. The
installer ran, but hit the "cannot create process" error when trying
to run instreg, and as a result, the whole installation failed.

c:\database is not the same disk as c:\program files.

FB 1.5 and FB 2.0 both install fine in this scenario.

FB 2.1 also installs fine, just so long as the installation
directory
is not part of a mounted volume.

There are other things that FB2.1 seems to get wrong, but I won't
bother with them until I am confident that this one is sorted, since
they may all be different flavours of the same problem.

Just to be clear:
If I re-create my VM so that c:\database is a regular directory on
the only disk that the VM has, the installation is fine. It only
appears to crap out when c:\database is a mounted volume.

Any ideas?