Disk Management 'System Drive' Issue

[Guest]

I have one 500 GB drive in three partitions: C, D, and E. I am attempting to
delete D (which is empty) in Disk Management, so that I may extend C (where
Vista is located) into it. However, D, for whatever reason, is marked
'System', while C is marked only as 'Boot, Page File, Active, Crash Dump'.
What can I do to make C the 'System' partition? I thought this was determined
solely by where the operating system was installed.

Vista was once located on D, but D has long since been formatted and Vista
reinstalled on C.

 

[Guest]

I had only formatted D (which had actually been E before installing Vista on
what had been D relettered all three automatically).

However, I was just a few hours ago able to do everything I needed to within
the Vista installation disc from boot. My goal in all of this was to get back
down to a single full-drive partition, and the installation disc allowed me
to delete Partition 3, then Partition 2, extend Partition 1 to encompass the
drive, then install Vista.

This did result in me doing something that I wanted to avoid: installing the
operating system somewhere other than the centre of the drive. I honestly do
not know how much this will affect anything, but I will try to rearrange it
later.