Replying to Serial Number to Uninstall?

So about a year ago I downloaded adobe premiere pro 1.5 tryout and soon after deleted it, since I found no need for it.

I am now trying too free up space on my computer and it is a pretty big file. I go to uninstall it asks for a serial number.
Why would I need a serial number to uninstall a program that was a 'tryout' and therefore required no serial number.

So, I either need tips on how to get rid of it, or some place where I can get a serial number, so I can get this file off my computer.

Thanks in advance for help
+k