Lost Hard Drive Space after Failed Ubuntu Install

[Mike Hoy]

I'm a bit of a Linux Novice. Not my first time setting up a dual boot 
environment but my first on this machine and my first time with Ubuntu. 
Here is my problem:

I attempted to install ubuntu on my Dell Dimension E510. I booted up in 
safe graphics mode and on the desktop clicked on 'Install'.

I made it to the partition section of the installer. I chose manually 
edit the partitions.

I tried to create a primary partition for Ubuntu. I clicked next and it 
was nonresponsive. Had to force quit.

Launched the installer again and chose manually edit partition table. 
The partition, according to the installer, had not been created, but did 
have an ! mark inside of a trinagle around my main partition (or C: 
Drive in windows terms).

I rebooted to windows to see if there was any problems. Checkdisk came 
up, said the volume was dirty. Checkdisk didn't do much except scan the 
disk, no repairs appeared to have been made.

Upon getting to my Windows desktop I opened My Computer. The harddrive 
once had 71.44 of hdd space, now had 35.6 GB of hdd space.

In Disk Management(local) it shows the C: being at the full capacity 
(71.44 GB).

I went back into the Linux Installer to see what it showed how my 
partitions were set up and it reported a main partition of 71.44 gb, as 
though no changes had been made at all.

In Short after trying to partition my hdd with ubuntu installer My 
Computer shows a C: drive with a size of 35.6 GB and Disk Management 
shows I have 71.44.

How do I recover my lost free space?

btw, I made a post on the Ubuntu forums but never received a response so 
I thought maybe you guys could shed some light.