LoL Client doesnt show after selecting launch

So...

The launcher works fine but when I press the "Launch" button the client doesn't show - however, it does come up in my task manager as running...

I have tried everything I've seen online:

-repair game -disable/uninstall virus software temporarily -delete files from C: drive folders (RADS etc.) -Open IE to help connect to internet

None of it works, I've been e-mailing the support team but nothing they have suggested has worked. The only way I've managed to launch a game properly is by doing a clean uninstall/install. However, I don't want to be doing that every other day to be quite honest.

Any advice would be appreciated!!

Cheers