Finder box keeps appearing--hard to launch programs

First off-I want to apologize if this thread has already been made, as I am new to this forum and a new mac user.

If anyone can be so kind to help me out here. I'm about to lose my mind here.

Everything has been great with this iMAC desktop for about 2 months now. All of a sudden the "finder" box? (DEVICES-Macintosh HD, iDisk SHARED, PLACES, SEARCH FOR, etc) keeps appearing non-stop...even after I keep deleting it. Every time I try to go to something it just keeps popping up over and over...very annoying

Now, after reviewing some sites on google I'm very confused because some say that it could be a Stuffit issue, "AVR" needs to be turned off, extensions, permissions, etc. I dont have a clue what that stuff is. I have already gone into the System preferences, but do not have an AVR icon or anything of that nature to turn off in the Other category.

Also note--this just happened right after I downloaded the Logitech software for my cordless mouse. I do recall the system asking me to save it/download with Stuffit--which I have no idea what that is--I just thought I was supposed to download the file with that program being such a new user.

Please help--sorry for the winded message.

Thank you-

Reese

you are downloading compressesed files. Stuffit is a program that will expand your files and make them usuable. here is the protocall: download the file <using stuffit if need be> click on that dl'd file to begin extraction of the files. once uncompressed, you should be able to run what it is you are trying to run. check this:
Apple - Downloads - System/Disk Utilities - StuffIt Expander
you can download it or learn about it. it is an unarchiving tool.