Can't boot from system partition, data loss imminent

Hi there,

I'm experiencing a big problem with my Win2k System
partition. Suddenly it was no longer possible to boot from
my regular harddisk any longer.

All partitions on the harddisk except the system partition
are still accessible. Partition Magic says it is error 1541
"Bad file record size" and I should run CHKDSK /f from the
recovery console.
http://www.powerquest.com/support/doclink.cfm?id=992

I don't trust that really because I have never seen CHKDSK
accomplish anything useful.

Does anyone have an idea how it came to this and - more
important - how I could solve this without loosing any
data. Unfortunately the last backup always seems to be just
a little too old, when you finally need it...

Thanks a lot!
Alex