How was the drive partitioned? With the 32.248gb only seen as a logical drive the creation of the partition seen at that figure depends on whether the total drive space available was reduced in the XP installer window or when using a 3rd party partitioning tool. If you only created a smal primary the 287gb approximate would be seen as unallocated drive space.
When going to partition a drive here I often use the Gnome Partition Editor which is a free Linux tool that can be used for creating new NTFS and Fat partitions as well as VFat types for Linux. It's an easy tool when you are splitting a drive up into more then one single primary. You can also use that to increase or reduce the size of a current primary or extended partition if you made a goof by reducing the size when going to install Windows.
For dual OSing and even custom installations on more then one partition GParted has been put to work here often enough. You simply download one of the free versions for cd found at
http://sourceforge.net/project/showf...kage_id=173828
On an Asus board you can go right into the bios and set the boot order for the ide drive after you have it partitioned the way you want it. The Linux tool will clearly detect a working drive even if you use another partitioning tool. That can even remove Vista partitions as well as creating new NTFS partitions for the new version of Windows to install onto.