If TechCheck installed anything, uninstall it via Control Panel > Programs.
McAfee TechCheck is only to be used when you are thinking about employing the Techmaster paid technical support service. It's merely a troubleshooting tool and wont fix anything whereas the McAfee Virtual Technician will.
The regular Technical Support is free of charge and available by phone or online chat and linked under Useful Links at the top of this page. You will be asked to run the MVT I just mentioned first.
You can suggest improvements to products here: https://community.mcafee.com/community/home/ideas Whilst 96dpi is the default setting for most displays I realise that it can be a problem for those with vision issues.
Lastly the Windows Firewall is switched off when McAfee Firewall is installed, so you can disregard that.
Is your software malfunctioning? If so we need more information, what version of the software is installed (open it and click 'About') and what operating system and service pack (if applicable) is this, and what version of Internet explorer is installed (even if you don't use IE, McAfee does so we need to know that). ?