No problem. It's more difficult to explain that it is to understand.
A wild card is just a method ued to sort of fill in the blanks to speed things up, from the old DOS days. Usually you see it used like this:
Example: I tell to you get rid of all the index files on your computer, and you know that index files end in the extension ".ndx" (menu.ndx, majik.ndx, etc). So when you go to do it, you notice there are 100s of them. So, rather then delete them one at a time, you could just type the command:
del *.ndx (your computer you now know to go ahead and get rid of all of those files that ended with that extension, no matter what the first part of the file name was)
With the instructions I gave you to fix your problem, it's kind of the opposite of my example. That is, there will be more than one file named estbcnfg, but they will have a different ending (for example, maybe there is estbcnfg.001, estbcnfg.002, etc). You want to delete any file that begins with estbcnfg (and ONLY those files).
You don't have to go to a DOS prompt to do this, since there shouldn't be a ton of these files. You can use windows explorer or my computer to go to the RMWIN folder, find the estbcnfg files, and delete them one at a time.
I don't know if that was the world's greatest explanation, but if you're still lost or confused--and it's ok if you are, computers may not be your thing--then you should probably not attempt this. If that's the case, either call your local dealer, or have a computer literate friend read this and see if they can understand it and help you.
This is not a complicated operation, but the folder you'll be in holds the core files for your POS system, and if you delete more than your supposed to, you could really screw things up.
I am also probably not the only paranoid tech around here who makes a habit of cutting and pasting files to an alternate location temporarily, to see if everything works-before offically deleting them. That way, if it does screw something up that you have no idea how to fix, you can always put those files right back.
Best of luck!