So you currently have w2k on. Alright here is some excerpts from the 127GB barrier sticky. For the short version see below. For the long go to 137gb barrier
W2K and XP users must have the latest service packs installed to access more than 137GB.
Q: Why is it called the 137gb barrier when the drive is shown as 127gb in windows?
A: 137GB refers to the metric number of bytes (as do hard drive manufacturers) in which the prefixes kilo, mega, giga etc are rounded to a multiple of 10. kilo being 1000, mega 1000000 and giga 1000000000. however computers operate in binary so the definition of these prefixes has been changed to fit the difference in numbers. for instance a kilobyte is actually 1024 bytes not 1000 bytes. therefore a megabyte is 1024x1024 and a gigabyte 1024x1024x1024 etc, binary quantities of bytes use an "i" in the suffix eg: MB vs. MiB and GB vs. GiB. so if the number 137,000,000,000 is taken (137gb) and divided by the number of bytes in 1 GiB (1,073,741,824 bytes) the number 127.59 results. hence 137GB=127GiB.