Game lauch bug

Hello, I have been playing League on and off for a while now and it has come to my attention that when I try and enter a game it slows down and loads VERY slow, now this is not an issue with the computer I am running and am having a tough time figuring out the problem. Ill wait for five minutes and all the character portraits will appear ( around 5-7 minutes into loading) At this point I realize that the game has disconnected and it asks me to check my network connection. I have had no problems connecting on my laptop nor on other computers that are used for league on this network and am quite confused to why this happening now. P.S. All other games on my system work without a hitch and I've been really bummed out as I wanted to take this summer to improve on league and strive for my highest rank that I can get. If anyone has any suggestions on how I could combat this problem I would appreciate it greatly. Thanks for your time -Nick