Expanding C volume in RAID 5 array

[Guest]

I have a Dell Poweredge 2600 server. It had 3 72Gb hard drives configured in
RAID 5 array with a single volume (136GB). I have just installed 3 additional
72GB hard drives, 2 as additional space and 1 as hot spare for the array. I
have reconfigured the RAID 5 giving me 272GB.
I tried to use computer managament (Dell Openmage Array Manager) to then
increase the volume. I received an error message saying "failed to extend
volume". I checked the comp management view again and found that it showed
272Gb for the C volume but when I use explorer, only the original 136Gb is
shown with the same amount of free space.
Any advice would be greatly appreciated!

 

[Bob I]

Perhaps the reason is

48-Bit LBA Support for ATAPI Disk Drives in Windows 2000
http://support.microsoft.com/default.aspx?scid=kb;en-us;305098

 

[Guest]

We are running SP4 so the below cannot affect my server. I have checked the
info in the link but shows ok. We are running "virtual disk" created by Dell
Openmanage array manager. Comp management still showing 272GB for C: drive
but explorer shows capacity of C: as 136GB (original size).

Any other suggestions?