Unless you are a legacy user with a valid license running a dedicated offline Windows 7 machine, hunting for a "full version" of Photoshop CS5 is a dangerous waste of time. The software is insecure, incompatible with modern operating systems, and the download sources are riddled with malware.
If you specifically need the "CS5 feel" without the cost, these tools are excellent substitutes: download photoshop cs5 full version
Go to Photopea.com . Close your eyes and click. Open it. It looks exactly like Photoshop CS5/CS6. It runs in your browser. It opens .PSD files flawlessly. It is free (with ads) or cheap for premium. For 90% of users searching for CS5, Unless you are a legacy user with a