No Access to local Drive c: (system Partition)

Hi there,

I have a very strange problem I never have seen before this way.
I have a Win2000 Std. Server running since 2 or 3 Years. Until 2 Months ago
everything was fine, but then from one Day to another I am not able to access
the Harddrive c:\.
The Server is a member Server in a Domain and we made no changes to any
Security or Group Policies.
If I open the "Workspace" I see all of my local drives and can access them,
exept
the c:\ one.
When I look at the Properties I see c:\ has 0kb Diskspace and 0Kb free space.
When I look in the Security settings I see there is NOONE with Access.
Gaining Access via (sorry I only know the German word) "Besitzübernahme" as
an Admin (-> Getting
all Rights on all files) does not work.
The strange thing is, that although there is NOONE with Access on the C:\
(there is really nothing listed) the
System starts properly from this C:\ Drive.
I tried almost everything but nothing worked. Because nothing can access the
c Drive, I can´t start any Test-Tools
or install or Deinstall some Programmes.

Has anyone ever had such a problem or perhaps knows a workaround to fix this
? I don´t want to install this Server completely new.

Thanks in Advance

Michael Thielen