First-time poster. I've had a Dell XPS One 27 for about two months now. The fonts in a couple of specific places have changed. They've changed from the standard Windows font to a different font (I don't know what it's called.) I noticed it first in Yahoo Mail in the browser. The font is changed in both Chrome and Explorer. So, I figured it was a problem with my Yahoo account settings or my browser(s) settings. I checked all of that out and nothing had changed. Then, today, I noticed that my McAfee Security Center app had also changed fonts to display the same fonts as Yahoo Mail. Here's a picture of what the fonts look like on Yahoo Mail and McAfee.

Click image for larger version

Now, I'm stumped. I don't know how the fonts changed. I certainly didn't make any changes that I'm aware of.

My Windows 8 has been doing a few weird things that may be related. Here they are in no particular order:
-It has hung up when restarting the computer as it tried to install updates. It got hung up (for hours) on update 14 of 14.
-When I restart my computer, upon booting back up, it says that I've been locked out of SkyDrive for exceeding the number of log-in attempts though I don't ever remember trying to log in.
-I installed the gTasks HD app and it won't sync with Google. The same goes with my GMail app. It syncs at first with GMail but then never updates again.

Any help would be greatly appreciated. Thanks!