I get that file.
open WFILE, "> default.asp?aa=1"
or die "Can't open default:$!";
print WFILE $data;
close WFILE;
---------------------------------
Depending on the file system that you are trying to save it to, you may not be able to. FAT and FAT32 don't allow '?' in the file name. And probably NTFS doesn't either (I'm not sure on that) looking at the extension I suspect that is probably the problem, you'll have to use another character.