My dad's computer has a 40G Seagate drive that has been acting up over the past month or so. It is partitioned as 15G for OS/programs and 25G data. Twice now for no apparent reason the D partition will lose format and of course all data. upon reformatting drive D and rebooting we get can not find ntldr and the system will not boot. Restart with WinXP CD and got to reinstall and now C drive is unknown/unformatted. We have run all Seagate diagnostics and no errors found. I am becoming very frustrated. Any ideas?