What do I need to do to get it to show as available?
I imagine the first thing to do is give your computer setup as per AMD Forum rules: INFORMATION REQUIRED WHEN POSTING A QUESTION
Your HD 6450 (only GPU Card shown in AMD Driver download page) is considered to be legacy (Non-Supported and old) The last Graphics driver for your GPU are from 2015 and BETA 2016; AMD Radeon™ HD 6450 Drivers & Support | AMD
If this is a LAPTOP it is best to use the LAPTOP's manufacturer Graphics Drivers so that Device Manager will show it correctly and detect it.
If by "VGA" you are talking about Microsoft Basic Display Adapter than it means your HD 64xx is not being detected by Windows. Are there any Errors showing in Device Manager like a Yellow Exclamation mark or Error code like 12 or 43?
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