Vista - Can't create 2nd partition on disk

I've got a Dell laptop (XPS M1710), wich has a 160GB drive, created a 'c:'
partition of 85GB during Vista Ultimate install, (a recovery partition of
10GB) and have 54GB of unallocated space.
I want to create a new 'drive' of these 54GB, so I right-click on it,
'create new simple volume' (only available option) and go through the
wizzard, and then after last screen I get the following message

There is not enough space available on the disk(s) to complete this
operation.

(I can choose quick format or not doesn't make a difference) I don't know
how to get it done,can someone help me out ?

TIA, Jurjen.

Jurjen de Groot wrote:
> I've got a Dell laptop (XPS M1710), wich has a 160GB drive, created a
> 'c:' partition of 85GB during Vista Ultimate install, (a recovery
> partition of 10GB) and have 54GB of unallocated space.
> I want to create a new 'drive' of these 54GB, so I right-click on it,
> 'create new simple volume' (only available option) and go through the
> wizzard, and then after last screen I get the following message
>
> There is not enough space available on the disk(s) to complete this
> operation...

I confess I don't know why you get that error, but my advice is not
to try to work around the error from inside Disk Manager.

I would suggest you try a free download of Acronis Disk Director Suite
from acronis.com and see what it has to say about your partition table
before trying to change anything.