Here are the steps to install TeX Live first and then SW without the TeX Live install:
It may be necessary to disable any antivirus software. If you are behind a firewall, this may cause problems and prevent using the over the network TeX Live installation (see the note below).
1. For Windows, visit http://tug.org/texlive/acquire-netinstall.html. On that page, click the link to install-tl-windows.exe to download the install file.
For Mac, visit http://tug.org/mactex/mactex-download.html. Click the link to MacTeX.pkg to download this install file.
2. When the download is complete, double-click to start the install. Follow the default installation instructions. Wait until the installation is complete, which may take an hour or more.
3. Start the SW/SWP installation. Be sure to use the current installer from our Downloads page.
4. On the Select Components dialog turn off "TeX Live Network Install"
5. Use the default selections for the remaining dialogs. Wait for the installation to complete. Be sure to Activate to enable full functionality.
NOTE: Some firewalls prevent using the over the network install. You can instead download a .iso image to install TeX Live. See http://tug.org/texlive/acquire-iso.html for information.
Additional install details
There have been reports that using the download file install-tl-windows.exe still results in errors during installation. As suggested by the download page, an alternative is to download the zip archive install-tl.zip. Unzip the archive into a directory and in that directory run one of the .bat files that launches the installer. Using the .bat file install-tl-advanced.bat generally is more successful. Install time using this method can be an hour or more, depending on your network connection speed.
The installer opens a terminal window and you will be asked for your password to be able to continue the installation.