You don't have to remember anything. Go to Finder, press Command+K, type smb://192.168.1.xx or smb://computername[SIZE=7] and press the + button. Your PC's IP address or host name will be there until you remove it from the list.

That's the name of the computer that you're trying to connect to.

If it's a Windows XP machine, you can right click My Computer, Properties. Click on the Computer Name tab. It the one listed as Full computer name.

I can't remember how you do it in Vista, but it should be pretty similar.

On the Mac, it's under System Preferences, Sharing.

Hope that helps.