Looking around from the clues you left. It appears the software most likely would be "Backup Exec" from Arcada Software. This software has been owned by Arcada, Seagate, Veritas and now is known as Symantec Backup Exec.
"A runtime version of the Arcada version was part of the Windows NT 3.5 and listed as "NT Backup."
MS Widows 95 has a built-in backup utility that was geared for tape drives. Maybe you used this one? Likely the 95 backup utility is an upgraded version of the one included in NT 3.5
A shareware version of the older Arcada Backup Exec is unlikely.
A popular utility for UNIX was "tar". A lot of programs used something similar. The name tar was derived from Tape ARchiver. There is a windows port for "tar"