If you haven't deleted those 3 scripts yet, try going to here:
http://localhost/cgi-bin/perltest.cgi or to
http://localhost/cgi-bin/printenv.pl
If it shows you something like "CGI with MiniPerl is ready ..." or prints out your system specs, than it meants that your server is runnning fine.
If it gives you error, than it means that you didn't started Apache correctly. Try going go XAMPP control panel and see if Apache is running. If not, try to start it and than try going to those addresses again. If it doesn't want to start, than it means that you didn't installed server correctly in which case you have to completely remove XAMPP (when you uninstall it also remove it's folder completely), restart your computer than disable ALL unnececary running background processes and try installing it again.
Also, no matter what the case is, make sure that (if you have it) IIS is completely disabled. To do so, go to Control Panel -> Administrative Tools -> Services look for IIS, right-click on the service than Properties and on the new window change Startup type to Disabled.