When i try to install Market updates/items it opens the wrong MT4 app, how do i change this? TIA
You can install it directly from your Metatrader:
After that - go to the Market tab, find Market product and install updates or installk the product.
If you can not find some product - use search function in Metatrader (on the top right corner of Metatrader).
Where can I see my purchases? https://www.mql5.com/en/forum/9950/page70#comment_2564931
How to Install an Earlier Purchased Application https://www.metatrader5.com/en/terminal/help/market/market_buy