Where is %SystemDrive%?

  • Thread starter Thread starter Steffen Haugk
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Steffen Haugk

Silly question: Where is %SystemDrive%?

For example
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SysmonLog\DefaultLogFileFolder
is set to

%SystemDrive%\PerfLogs

but where is that?


In contrast,
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Dfrg\PathName
is set to

%systemroot%\system32

and I know where %systemroot% is, because
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows
NT\CurrentVersion\SystemRoot
is set to

C:\WINNT

That makes sense.

I know it's kind of stupid, but I can't find %systemdrive%.

Thanks everyone.
Steffen
 
Steffen Haugk wrote in
Silly question: Where is %SystemDrive%?

For example
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SysmonLog\Defa
ultLogFileFolder is set to

%SystemDrive%\PerfLogs

but where is that?


In contrast,
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Dfrg\PathName
is set to

%systemroot%\system32

and I know where %systemroot% is, because
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows
NT\CurrentVersion\SystemRoot
is set to

C:\WINNT

That makes sense.

I know it's kind of stupid, but I can't find %systemdrive%.
Click to expand...

Open a cmd.exe prompt.
Enter SET

The %systemdrive% should have a value of the "boot" drive. Often
this is "C:". The drive that contains %systemroot% (the Windows
Installation location).
 
There are no silly questions. Only silly people who refuse to ask when
they don't know.

%systemdrive% is where the primary boot volume and OS are. So if you
install it to the default it will be C:\

Cheers
Peter Z.
 
Steffen Haugk wrote in


Open a cmd.exe prompt.
Enter SET

The %systemdrive% should have a value of the "boot" drive. Often
this is "C:". The drive that contains %systemroot% (the Windows
Installation location).
Click to expand...

I can not (or better, want not) run SET on a remote machine from my
program. I can happily connect to a remote computer's registry and get
%systemroot%.

I assume that %systemdrive% is the drive letter part of %systemroot%.
Although that makes sense, I wonder if that is the official way to do
it, and if that is the official way in which %systemdrive% is to be
interpreted.


Thanks for the reply.

Steffen
 
There are no silly questions. Only silly people who refuse to ask when
they don't know.

%systemdrive% is where the primary boot volume and OS are. So if you
install it to the default it will be C:\
Click to expand...

It seems funny to use a variable %systemdrive% in the registry and not
defining it anywhere.

Thanks,
Steffen
 
In said:
It seems funny to use a variable %systemdrive% in the registry and
not defining it anywhere.
Click to expand...

There are several variables that are created by the system at boot
time and are assigned dynamically. These are not defined (hard-
coded) anywhere. They are "defined" and visible in the local
machine's environment space. %systemdrive% is available if you can
read the local environment (on a remote system). psinfo.exe is an
example. psexec.exe is another way to see a "local" environment.

If you must read the remote registry to determine the "systemdrive" I
suggest
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\
SystemRoot=
(a REG_SZ) value. Then parse out the drive letter.
 
Thanks all,
I am satisfied I haven't missed anything. If systemroot is c:\winnt it
is kind of logical that systemdrive is c:, isn't it?

But why introducing it at all, when it is so obvious?
Why is systemroot not defined as &systemdrive%\winnt?

The weird world of Windows.

Thanks again,
Steffen
 
In said:
Thanks all,
I am satisfied I haven't missed anything. If systemroot is
c:\winnt it is kind of logical that systemdrive is c:, isn't it?

But why introducing it at all, when it is so obvious?
Why is systemroot not defined as &systemdrive%\winnt?
Click to expand...

A good question to which I have not the answer. :-)

It may be (hypothetical) that this derives from design decisions made
in the original NT developement.
 
Good evening,

The folder is situated on the C;/ drive under the following:

C:\Users - Public - Public Documents

Regards,
 
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