The fonts were not changed after installing Remo Optimizer but it has changed after installing the latest Windows Vista update "KB3013455"
We would suggest you to check the "Installed Windows Updates", find "KB3013455" and uninstall it. Also, uncheck it and hide it so that Windows would not reinstall it.
Steps to uninstall Windows Update "KB3013455": Start → Control Panel → Programs and Features → View Installed Updates. Locate KB3013455, double click on it or right click and select "Uninstall" and proceed with the onscreen instructions to uninstall the update.
Steps to hide Windows Update "KB3013455": Start → Control Panel → Windows Update → Click on the Available Updates. Right click on the Update KB3013455 and select "Hide Update".