Client Repair Failed?

So, this bug has just started happening to me recently, and is really starting to irritate me. I will be playing league for a few hours before work with friends, and everything runs fine. I will turn everything off after closing the client. A few hours later my shift ends and I get home. I turn on my pc, and start league.

A repair window opens and fluctuates for a few seconds going from around 1% to 90% to 50% to somewhere in the 30s. It then sits there for several minutes before giving me a "Repair Failed" message.

I don't know of any reason for my client to require a repair, but I think nothing of it. I reinstall the game over the course of a few hours and get on with my life.

Fast Forward to today, I get home from work and the same thing happens. I don't want to have to reinstall league every time I get back on. Has anyone else experienced this problem? If so how did you fix it?