I have an older media box as above and while it still works somewhat it no longer has all the functionality it had before and can't be used to search the internet etc. I would like to install a version of Linux on it if possible to be able to use it. Tried searching the Internet but nothing specific so I was hoping someone here may have the details on how to do. When it worked as it did originally I had access to Google Apps etc and could search the Internet with Chrome. Would like to be able to do so again. I was thinking of somehow getting Linux on a microSD and flashing to the unit. These are the specs of the box:

Processor: ARM Cortex Dual-Core A9 1.5 GHz CPU
Graphics: Mali Dual-Core 400 MHz GPU
Memory: 1GB DDR3
Integrated Storage: 8GB eMMC
Wireless: 802.11 B/G/N (up to 300 Mbps) + Bluetooth 4.0
Card Reader: microSD (up to 32GB)
USB Ports: 2x USB 2.0 Ports
Ethernet: 10/100 Mbps
HDMI: 1.4
Optical Audio: SPDIF

I understand it came with TOFU installed by Pivos Group but also had Linux on it although I can't say I ever saw that. Any help ideas thoughts would be greatly appreciated.

I wouldn't hold out too much hope.

Cortex A9 is a 32bit cpu. The number of 32bit operating systems is diminishing. There is slackware Arm on LQ as a subforum of the Slackware forum, and you can ask there. It's not getting the OS that's the hurdle, it's the boot process. Most sbc & sticks like your own had individual booting systems. There's some effort now to standardize boot, but afaik it's a WIP.

So if you can get your stick to boot a kernel and load any firmware required, you may get there. Otherwise, give up. If you bin it, you haven't lost much.