drvmain.sdb is missing or corrupt

Greetings!

All of a sudden get this message:
drvmain.sdb is missing or corrupt

1. booted from MS CD and used R option when set up
2. while restoring files from CD had to skip multiple files as there was an error either reading or writing the files...
3. eventually get a blue screen ....
4. rebooted windows and had to restore to the first successful conf.
5. get back again to drvmain.sdb ...
6. safe boot to command prompt causing blue screen...suggesting checking for viruses or run chkdsk /f

Please, help!

Thanks!