1) Chimp Rewriter is a Windows desktop application. It is not a website or web application. It must be installed on your PC.
2) To download the latest copy go to http://chimprewriter.com/download in your browser and hit the download button. It should automatically begin downloading.
3) Once downloaded, browse to the download location using File Explorer. The filename should be ChimpRewriter-Setup-vxxxxxx.exe (the xxxxxx will change depending on the version number)
4) Double click the executable. It should display a windows installer. Click Next a few times to install it.
5) Using the start menu, go to Programs/Aktura Technlongy/Chimp Rewriter/ and click on the Chimp Rewriter menu entry
6) The first time it runs, you will be prompted for an email address and password. Enter your payment email address and create a password. If you are signing up for the Basic version, just enter an email and password and tick the box to sign up to the newsletter. Proceed to step 6a.
6a) (Basic version users only) Check your emails. It could take up to 5 minutes, but eventually you will be sent a confirmation email. Confirm it.
8) Click next in the registration wizard (with Chimp Rewriter) and it should register OK.
9) Chimp Rewriter will automatically begin downloading the latest thesaurus.

If you get to the end of step 9 then Chimp Rewriter is good to go.