How to browse the web on old computers

For Windows 2000 or earlier see How to browse the web on very old computers This guide is made for people who want to browse the web on Windows XP or Vista after most browsers have discontinued support for them.

Make sure to enable SSL 3.0 for old versions of Internet Explorer so you can access certain HTTPS websites. You can do this by navigating to Tools > Internet Options > Advanced > Security and ticking the SSL 3.0 box.

Mypal: A Browser For SSE2 Computers
Try this browser first if you do not know whether your PC supports SSE2 or not.

Visit the Mypal download page and download the applicable version for your CPU architecture. If you get an error about SSE2 during installation, go to the next chapter. Otherwise, you have successfully installed a functional, updated web browser on your legacy system!

New Moon: A Browser For Non-SSE2 Computers
Setting up New Moon is a bit more complex than Mypal, as it has no installation process and comes with all of its files decompressed out of the box. However, the package is in 7z format, meaning you will have to install 7-Zip as well.

Installing 7-Zip

 * Go to the 7-Zip download page. It may show an HTTPS certificate warning on Internet Explorer; just ignore it.
 * Download and install the 32-bit version. As 7-Zip does not require SSE, there is no problem related to that.

Downloading New Moon

 * Go to the New Moon download page. Download the most recent 32-bit SSE1 (the versions with an  suffix) version before trying the most recent 32-bit version without any SSE (the versions without a suffix).
 * Open 7-Zip and extract the version of New Moon you downloaded into a folder. If it works, congratulations! You have successfully installed a working browser on your legacy system without SSE2. If you did not successfully install the SSE1 version, try the version without SSE.
 * You can also use roytam1 Browser Installer to download and install it easily. Get it here