invisible client

Hey,

I do not exactly know when or by what cause it happened, but my client is not visible on my laptop screen, I have been trying to fix it with tips from other discussion, but it is still bugged. The only thing visible is a little white bar in the top left corner of where my client usually is, the sounds of the client also work and I can clink on thing in the client(don't know what though since I can not see it). The client is visible when I add a second screen, but then I can only operate it on my second screen. This way I tried to run a game (practice tool) and it worked on my original screen, so only the client is bugged. Anyone know how to fix this? I have already tried reinstalling LoL twice, does not work -_-

I hope someone can help me.