I've managed to flash Cyanogenmod 12.1 onto my Nexus 7 2012 to give it a new lease on life, but now I can't connect it to my PC to view it as a storage device!
The Nexus 7 shows up as a "media device" in Devices and Printers and does not show up as a drive in My Computer - the driver for it is shown as the Android ADB Driver. The Nexus 7 is only charging when connected to my computer, there is no notification to choose the connection type. I have tried re-installing the driver, but Windows says it's already up to date. ADB and Fastboot both locate the device in Recovery and Bootloader, so the driver is obviously working. Connecting the Nexus 7 to a different computer that hasn't been used to flash images shows up as a storage device with no problems.
What am I missing/doing wrong with my computer that won't show my Nexus 7 as a storage device?
Clarification: Running Windows 8.1. Connected with MTP mode shows my Nexus 7 in my Devices and Printers (but Unspecified), but not as a Media Device in My Computer:
Connected with PTP mode works as expected: