Maxtor OneTouch External Drive and Huge Files

I bought the Maxtor OneTouch external HDD, a 200 GB beauty, to try to manage my increasibly unmanageable number of VPCs that I need to run at any time.  The typical VPC that I use seems to run somewhere around 5 GB - 6 GB, depending on what I did to the image.

Every time I try to write the .VHD file to the external drive, I get a "disk full" error.  I bought a USB 2.0 card for my laptop (highly recommended, this thing speeds up USB transfers SO much!)  I thought that it was possibly some weirdness with the transfer going over USB 1.1 and being so slow.  The USB 2.0 card definitely speeds it up, but I still get the error.

After looking for awhile, I found the answer on Maxtor's web site:

Windows will report this error when writing to a file that has reached the maximum size for that File System.

FAT32 has a 4GB (gigabyte) limit.
NTFS has a 1TB (terabyte) limit.

1394 and USB Personal Storage drives are pre-formatted in FAT32. Therefore, if the backup file is larger than 4GB, a file size error will occur.

Great.  Except that I have already written a huge amount of data to this thing.  I found documentation for convert.exe to convert from FAT32 to NTFS, hopingly without losing my data.  Crossing my fingers....

Update:   Whew! Worked like a champ.  Convert.exe converted to NTFS, no problems (although I had to run chkdsk on the volume first), and now I can copy files greater than 4 GB.  Sweet.