Are you talking about Windows clients?
If so, go to www.coderelief.com, look in the SCRIPTS depot under  TSM
Scripts, the Disaster Recovery thread.
I've posted procedures for restoring WinNT and Win2K when the OS has failed
(on this list we generally call that a "bare metal" restore).

You are right that TSM on WinNT can't restore the files that are in use, but
the posted procedures explain how to get around that.  TSM on Win2K can (by
marking the file for "replace on boot").  The posted doc should help...