Problem Seeing 2nd Drive After Linux Installation

[martin4 na netactive.co.za]

Hi,

Hope you can help! Just installed CorelLinux in the DOS/Windows98 partition. When restarted Windows, everything was in order - could see both my drives including CorelLinux load file. After third re-boot, my second drive just vanished from sight in Windows and DOS. What could be wrong? How do I access my 2nd drive? Also have Windows files on it which I cannot afford to lose. 
Thanx
Martin