Please could you confirm the version of ActivInspire which you are using? To obtain this information launch ActivInspire and select Help>About.
The version will be listed at the top of the window that appears.
If you are using a version prior to ActivInspire 2.4 please upgrade the software using Help>Check for updates.
If the font and icons are still too small, click on File>Settings and select the Layout tab.
Here you will be given the option to change the Icon size. Please adjust and see if this helps with the issue.
Fingers crossed this helps, if not please let us know.