Adobe has officially discontinued Creative Suite (CS) products, and they are no longer available for direct download from the official Adobe website Existing Owners:
A quick Google search for "Adobe Illustrator CS5 Windows 7 32 Bit download" will yield dozens of results from torrent sites, file-sharing forums, and “crack” websites. Common risks include: Adobe Illustrator Cs5 Windows 7 32 Bit Download
QuickTime 7.6.2 and a broadband internet connection for initial activation and online services. How to Download and Install Adobe Illustrator Cs5 Windows 7 32 Bit Download
Since Adobe has removed the CS5 download links from their direct servers, the most reliable source for legacy installers is often community archives. Internet Archive (archive.org) Adobe Illustrator Cs5 Windows 7 32 Bit Download