Redeeming an Adobe Creative Suite 5.5 Master Collection - Old Version key is really simple, just follow these steps:

1. Download both links.
2. Run the .exe file to proceed with the installation.
3. Activate the product using the serial number for the product. 

For the English language use the below links:

https://trials.adobe.com/AdobeProducts/legacy/99CABBAC-C975-4A06-8D99-064C6871EE80/STAM/CS5_5/win32/MasterCollection_CS5_5_LS1.7z 

https://trials.adobe.com/AdobeProducts/legacy/99CABBAC-C975-4A06-8D99-064C6871EE80/STAM/CS5_5/win32/MasterCollection_CS5_5_LS1.exe 

For other languages use the below links:

https://trials.adobe.com/AdobeProducts/legacy/99CABBAC-C975-4A06-8D99-064C6871EE80/STAM/CS5_5/win32/MasterCollection_CS5_5_LS4.exe 

https://trials.adobe.com/AdobeProducts/legacy/99CABBAC-C975-4A06-8D99-064C6871EE80/STAM/CS5_5/win32/MasterCollection_CS5_5_LS4.7z 

The key is not working

If you have activated the key according to the guide but the code appears not to work, please check what type of error message you receive and depending on it follow the appropriate instructions: 

• My key is Duplicated / Already used
• My key is Invalid
• My key is region locked / can't be activated in my country
• My key activated a different product
• My key did not activate all of the content