Following on to the replies from GrandFather and AnomalousMonk, (and inferring from "IIS" that you're on Windows) try running this from a C:\ prompt:

perl -v

which should give your something like

This is perl, v5.n.n....

and, in the final para, three sources of help. The last two will be relevant if you're on Windows.

If you don't see that output, check that Perl is on your path.

If you do get version information, try running:

perl -c path_to_script_name.pl

(for either script, or both)

If that exercise returns "syntax OK", perl is working and your scripts are OK, in which case you clearly need to follow GrandFather's implicit advice: Read The Fine Manual (well, we can hope it's a fine manual) on IIS and its requirements for executing ( CGI ) scripts.