dvd decrypt help

[garfar]

Hi All I Am new to dvd burnin and are Running win xp pro have tried to use dvdencrypter came up with fat 32 > 4gb now ive gone to system/ admin tools/-disk management where do i click to convert --how do i convert to ntfs without loosing files or do i have to completly format and re-install win xp..if so when and how do i convert to Ntfs System
all help really appreciated are so confused thanks