WinRAR is a popular file archiving and compression Software that is available in both 64-bit and 32-bit versions. Here's how you can download and install Winrar v5.70 in both 64-bit and 32-bit versions:

1. Go to the official WinRAR website at www.win-rar.com.
2. Click on the "Download" link in the top menu.
3. Scroll down to the "WinRAR x64 (64 bit) 5.70" or "WinRAR x86 (32 bit) 5.70" section, depending on whether you want the 64-bit or 32-bit version.
4. Click on the download link next to the appropriate version to start the download.
5. Once the download is complete, double-click on the downloaded file to begin the installation process.
6. Follow the on-screen instructions to complete the installation.

Note: WinRAR is a paid software, but you can use the trial version for free for a limited time. After the trial period ends, you will need to purchase a license to continue using the software.