Mystery 20GB 'unallocated' on C:

jonnyg · 1 Mar 2006 at 23:36

Hi,

Having just setup my new HDD, i noticed in the disk management, that there was 20GB on my C: drive missing. It has been sat 'unallocated' since i re-installed Windows a month ago. I'm not sure how i missed that, but its a mystery to me how it happened. I did not setup Windows to have a 140GB C: drive (the drive is 160GB) but yet, there it is, 21GB of my physical C: drive not doing anything ('unallocated' as mentioned).

For the time being, i have set it as I:, as a separate drive, but this is not how i want it to stay. Is there any way of joining the drive back together, to form a complete 160GB C: drive, and as it is a boot drive, will this cause a problem?

Alexrose1uk · 2 Mar 2006 at 00:01

What version of windows do you have?

Overlag · 2 Mar 2006 at 00:03

Alexrose1uk said:
What version of windows do you have?

to the OP i think ALEX is on the right track, XP doesnt support HDD's over 127gig, you need SP1 (or is it SP2?)

Jeff Crawly · 2 Mar 2006 at 00:18

Overlag said:
to the OP i think ALEX is on the right track, XP doesnt support HDD's over 127gig, you need SP1 (or is it SP2?)

Not totally true!!

The OP clearly demonstrates that standard XP does indeed support Hd's over 137Gb (not 127Gb) but does not support partitions over 137Gb!

To create a partition over 137Gb you need either SP1 or Sp2 as these have 48-bit Logical Block Addressing (LBA) support.

However creating a C: partition of this size is just plane stupid imho

Overlag · 2 Mar 2006 at 00:40

Jeff Crawly said:
Not totally true!!

The OP clearly demonstrates that standard XP does indeed support Hd's over 137Gb (not 127Gb) but does not support partitions over 137Gb!

To create a partition over 137Gb you need either SP1 or Sp2 as these have 48-bit Logical Block Addressing (LBA) support.

However creating a C: partition of this size is just plane stupid imho

well yeah, not totally true if you want to be picky, i mean it will "work" on a 500gig drive, but why would you only want 137gig of that 500 to be access able (i know about partitions as i cant live with a pc without them...)

most people install there PC's with ONE whole partition though.

bledd · 2 Mar 2006 at 06:53

you should install xp with sp2 slipstreamed into the disc to avoid this problem

jonnyg · 2 Mar 2006 at 11:31

Its never been a problem before... Multiple times, using the same XP disc, and using the same hardware. All i really need now is a way of joining the disc back together.

smids · 2 Mar 2006 at 19:07

Partition magic is the best way.

I've found using disk part from the command line doesn't work....might be worth a try though, I believe the HDU Forum sticky has a guide... especially as Partition magic costs...