WinMend folders are created by codebreaking enthusiasts and not by software companies who want to sell you a virus or spy ware product. Win Mend folders are small programs that are designed in assembler form to work by hiding files from Windows when Windows tries to open them. They work by first loading up a small section of the Windows system's registry which has the file(s) you want to hide and then bypassing all other parts of Windows that attempt to load them.
The WinMend folder hides files the same way a typical virus would, by inserting codes into the executable files it wants to execute. To use this software, you first need to download it, then install it and then let it run. Unlike many similar programs, WinMend folders are small and highly optimized for speed. If you're going to use it on your home use, then you'll probably be able to get away with using it without any problems, but if you have any sort of important files that you want to keep private then it's best to let Windows do its job instead.
Many of the file types that WinMend folders hide are not normally found on home PCs. Most of these file types are more commonly associated with freeware, or other types of "open source" software, and are therefore not normally found on home PCs. Examples of software that can help you to find files that WinMend folders hide include: WinFinder, HijackThis, and others. These programs often help you discover the file types that WinMend folders use to disguise themselves. If you're looking for more help on the subject, I'd be very happy to help!