Help with Win32 Error

[SuRroundeD By 1]

I've been trying to download League of Legends so that I can play it with a few of my friends. I've made an account and everything; however, whenever I try to download the game, it begins by downloading PMB (Pando Media Booster) which is required to download League. The downloader will begin but before it ends, an error message will pop up. So I go directly to the website to install Pando directly from them, still, the download gives me an error message, this time more specific:

C:\User\Users\Downloads\P MBInstSafe.exe is not a valid Win32 application.

I've run into this error before, but the usual methods I use to get around it (ie: restarting computer, disabling anti-virus for a minute, anti-virus full system scan) have not worked. I'm currently trying my disk defragmenter but I have low hopes of that working to. Please help?

I've tried to Pando forums, the waypoint forums, and google, and I can't figure it out . . .

[SuRroundeD By 1]

Disk Defragmenter did not work . . .

[Zucav]

you shouldn't need PMB to play LOL. i think what you've downloaded is just PMB..
Last time i downloaded that it was all wonky.. I just uninstalled it and found a new source for the download.. whats your source for the .exe?