Some users have been reporting that their CPU goes up to 100%, and their screen freezes when hitting the "play" button, including myself - with Intel CPU's. There is a temporary fix to that.
The bug is not related towards the CPU/GPU. It is outdated Killer Network drivers on MSI motherboards.
For those with the MSI-Z87 G45. Download the updated Killer Network drivers from MSI's site (found here: http://us.msi.com/support/mb/Z87G45_GAMING.html
Scroll down to "support" then click "driver," select your OS then download the latest Killer Network drivers (found towards the bottom.) Once the newer driver setup is downloaded, UNINSTALL your current drivers in control panel, reboot your pc (you won't have internet access.) Next, install the drivers you downloaded on MSI's site by running setup. Afterwords, reboot and you will beable to play Dota 2 just fine!