Basically Total Commander (formerly known as Windows Commander) is a file manager with two separate windows with a lot of extra features. Total Commander also gives you a lot of the file info that in Windows Explorer requires you to right click on a file and select properties.
Another important difference between Total Commander and Windows Explorer is that Total Commander also is designed to be used using only the keyboard, where Windows Explorer in general is hard to use without a mouse.
If you have previously (in the old DOS days) used Norton Commander, using Total Commander will come naturally, as many of the keyboard shortcuts are the same.
Just evaluating Total Commander as a Windows Explorer replacement would not be fair. Total Commander has a lot a features that allows it to replace a number of extra utilities that you might have installed. It has built-in file transfer, it has an FTP client (that even supports FXP (direct data transfer between 2 FTP servers)), it has a built-in icon bar where you can create shortcuts to your favourite programs and utilities, built-in system information, a multi-rename tool, network connections administration, file type associations and compression utilities such as zip, arj, lzh, rar, uc2, tar, gz, cab og ace.
Calling Total Commander the computer user's Swiss Army Knife wouldn't be far off - The programmer comes from Switzerland...
Total Commander can be used with all versions of Windows (even Windows 3.x), Windows CE, Pocket PC and Smartphone. It can, as mentioned above, replace a lot of different programs taking up space on your hard drive. Total Commander is so compact, that it only takes up around 20 Mb, so you do not need to go out and buy an additional hard drive to install it...
Total Commander works with all Windows versions in both 64 and 32-bit versions (even a 16-bit version for Windows 3.x), there is a version for Windows CE, Pocket PC, Windows Smartphone and Android.