UnRAR-ing a file is just the opposite of RARing a file, as one might guess. Basically, you are undoing the RAR format and then extracting the files content. If you are an end user, this isn't a big deal if the WinRAR comes with an UnRAR option. If there is an option to UnRAR, you simply have to click the button, and just as when you unzip files, the RAR file will be extracted to the folder of your choice.

It's not uncommon during the UnRARing of a file to have a dialog box pop up and state that the archive is corrupted. This typically happens when you are trying to UnRAR a file that used an earlier version of the WinRAR than the one that you are using, which is likely WinRAR 3.2. The reason that these two versions don't work together is that there is a different compression rate used by WinRAR 3.2 than was used in the earlier versions of the program. The best thing you can do if you come across this problem is double check the version of WinRAR you are using and update if necessary.

You should be careful when you are UnRAR-ing that you are extracting the files you want to peruse to the correct location and that there is no threat of overwriting files you have already created with the same name. WinRAR is a very useful program for compressing various files, but you need to be careful in extracting things without replacing those that you didn't intend to replace. You will no doubt find the documentation and information that comes with WinRAR very helpful in learning to RAR and unRAR files appropriately.