WordSmith Tools version 5 is for Windows 2000 or later, including Windows 7 (either 32 or 64-bit versions). It will be happiest on a fairly modern PC (e.g bought in the last 4 years) with plenty of memory and hard disk space. Or an Intel Mac.
Installation and Running WordSmith 5
If you downloaded the self-extracting setup.exe file, just run it: it will help you expand the contents into c:\Program Files\wsmith5 or wherever you choose. All the files must be put in the same folder.
To install, all you need do is be sure you have all the files in the same folder. (Of course you can put your wordlists and concordances wherever you like, eg. in sub-folders of \wsmith5 or on quite different drives; you only need ensure all the program files -- the ones you downloaded -- are in the same place.)
To start using WordSmith 5, run \wsmith5\wordsmith.exe. You will be asked to agree to Terms & Conditions then will be taken to an updating window (\wsmith5\WSRegister.exe) which will allow you to type in the username and registration code. It'll also allow you to put an icon on your desktop.
If you have never used WordSmith, you may find it best to choose Help | Contents | Getting Started, or | Overview in the menu.
Once you have WordSmith 5 up & running, you can update automatically by choosing File | Web Version Check in the main menu. This will check the version of each file you have against the same table (at www.lexically.net/downloads/version5/wordsmith_versions.htm) and will know what needs to be updated.