What makes no sense here is that the lack of 48-bit LBA Support would limit the Partition created to 128 GB, NOT 160 GB. Are you SURE the drive says it is 160 GB?
If it really does say 160 GB, then you do NOT have missing 48-bit LBA Support. You do NOT need to update your BIOS or install other Service Packs. The ONLY way you can actually get a 160 GB Partition is if 48-bit LBA Support is already present.
Now, if you DO have a 160 GB drive, then somehow you actually created a Partition of that size, apparently not what you wanted. If this is NOT your boot drive - that is, if it's a data drive not named C: - then you should be able to Expand the Partition to add all of the Unallocated Space still on the drive unit. Warning: this sort of operation CAN go wrong and you could lose all your data! So ALWAYS do a full backup of that data on the drive before proceeding.