Installing

I spent 5 hours with Microsoft Support remotely controlling my computer to try and resolve this issue and they told me to come to you after they were unsuccessful. I do not have League of Legends on my computer at this moment. Not a single folder or anything, but when i go to uninstall programs League of Legends is there. When i try to uninstall it does not let me, this is what pops up "The feature you are trying to use is on a network resource that is unavailable. Click OK to try again, or enter an alternate path to a folder containing the installation package 'LoL.NA.msi' in the box below." Use source: C:\Users\Mike\AppData\Roaming\Riot Games\League of Legends 4.1.1\install\ Then i hit browse and it brings up nothing. Or i use source Disk 1 and nothing comes up. SO i hit cancel and it says "The installation source for this product is not available. Verify that the source exists and that you can access it." So if i try to re download League of Legends it pops up during installation that "An older version was found and that it cannot proceed. Please help i have tried everything for days and cannot get this fixed. I am currently Plat 2 and i play A LOT, this definitely stinks as the season is coming to an end. Please resolve this as soon as possible. Thank you!!!