New Dell Laptop Freezing while Browsing the Net

I have this model XPS Ultrabook.

Every few days, I'm browsing any given site and the computer freezes. Can't move the mouse. Can't use the keyboard. I'm 28 and have used PCs since age 5. I work in IT support. I know how to identify symptoms. This thing is frozen, requiring a hard reset. I'm pretty sure it only happens when running off battery.

So you boot it back up in normal mode, and there aren't any "Windows has recovered from a serious error" messages to help me further. Here's what the event log says about the events leading up my restart:

1. The speed of processor 0 in group 0 is being limited by system firmware. The processor has been in this reduced performance state for 82917 seconds since the last report.
2. The speed of processor 1 ......(same thing).....
3. The speed of processor 2 ......(same thing).....
4. The speed of processor 3 ......(same thing).....
5. The start type of the Windows Modules Installer service was changed from demand start to auto start.
6. The start type of the Windows Modules Installer service was changed from auto start to demand start.
7. The Windows Modules Installer service entered the stopped state.

And then it's frozen. But look, the event log for the previous 4 freezes has entirely different events. Sometimes, nothing is logged for minutes up to the freeze. It just says "the computer was unexpectedly shut down." after I reboot it. Duh. In other words, there's no consistency. Nothing I listed above happened the previous 4 times it froze.

I've switched browsers from Chrome to Firefox...same problem. What would you do in this situation? If the two most common browsers don't work, what could possibly fix this? What would you do?

Any help is appreciated. Thanks.