Adobe Illustrator CS5 introduced several groundbreaking features that streamlined the design process:
QuickTime 7.6.2 and a broadband internet connection for initial activation and online services. How to Download and Install
Adobe has discontinued official support and direct public download links for CS5. However, if you already own a valid license, you can still install it: Can I download my older CS5 apps? - Adobe Community Adobe Illustrator Cs5 Windows 7 32 Bit Download
Manage up to 100 artboards in a single document with a dedicated Artboards panel to organize and name them easily.
1024x768 resolution (1280x800 recommended) with a 16-bit video card. - Adobe Community Manage up to 100 artboards
1GB minimum (2GB is recommended for better performance). Hard Disk Space: 2GB of available space for installation.
To run Illustrator CS5 smoothly on a 32-bit Windows 7 machine, your hardware should meet these minimum specifications: Intel Pentium 4 or AMD Athlon 64. Hard Disk Space: 2GB of available space for installation
The Width tool enables you to dynamically adjust the thickness of a path at any point, creating expressive, variable-width strokes. System Requirements for Windows 7 32-Bit