Is it possible to download Ubuntu 15.04 directly from the main site to my laptop as a clean install to rid issues "PCC Probe failed" with Ubuntu 15.04 running now? I'd like to know why it is so difficult to install or overwrite and clean install Ubuntu 15.04 from the Ubuntu website? Why must "we" go the roundabout method of getting a USB stick formatted, then the OS downloaded to the stick beforehand? Why the hassle over Open Source? Having "hurtles" is not going to convince a skeptical public full of Windows and Apple users to consider Linux if installation more like "skinning the cat." Why not offer preformatted USB sticks that will overwrite if necessary and perform "Clean Installs?
First of all, that message is a warning and not an error. The failed probe message is of absolutely no consequence (you can ignore it). See here: https://askubuntu.com/a/584875/167115
If you want to buy a preinstalled Ubuntu disk, you can do so from the Ubuntu store:
Also, windows and OSX both have the system limitation of not being able to install over a running OS. In fact, both Windows and OSX require you acquire installation media, from microsoft or the istore or whatever. Both Windows and Apple offer the option (of convenience) to download the OS installation media in the form of an ISO or DMG respectively. Granted, you can boot the dmg on a running OSX to start the install, I believe the system boots you out of the regular session to do so.
If you would rather do all the downloading during installation, you can use the netboot or mini.iso version available here:
Don't like or even care about opensource? Maybe the opesource community is not for you.