i may be wrong, but i think it's /sbin/modprobe ... at least, thats what it is on my mandrake system
are you running it as root?
try running this:
Code:
[scuzzy@localhost scuzzy]$ su
Password:
[root@localhost scuzzy]# updatedb;locate modprobe
you're looking for an executable, probably in /bin /sbin or, for some wierd reason, /usr/bin