I have a Dim 2350 about 8-10 years old and in need of a hard disk upgrade.  What is the largest drive I can install that will work with the my current A01 Bios?  Will I need to upgrade the Bios to A02 for a larger capacity?  I have a Maxtor 6E040L0 40g now with about 13g left. 

Using Windows XP SP2 but it may have been SP1 on the original OS CD.  That has been missing for years, can that be replaced or must I go with a new XP OS?  Any help would greatly be appreciated very much.