I am assuming you are talking about Spotfire Analyst, If you want to install Spotfire analyst 7.6, you will need to uninstall existing spotfire analyst 7.10 completely and install Spotfire 7.6. As soon as you connect to your spotfire server ( which I assume is 7.10) it will again pop-up to install update, you can select no at that time to keep your spotfire analyst to 7.6.
How to clean uninstall SPotfire analyst:
1. Make sure all TIBCO Spotfire Client products are uninstalled using the Control Panel.
2. Delete any remaining files in C:\Program Files\TIBCO.
3. Delete any remaining files in C:\Program Files (x86)\TIBCO.
4. Delete any remaining files in C:\Users\<username>\AppData\Local\TIBCO.
5. Delete any remaining shortcuts on the desktop to TIBCO Spotfire.
6. Delete any remaining start menu group for TIBCO Spotfire.
7. Start regedit and delete the “TIBCO” key (if present) in :