First, make certain the machine is fully updated. Go into updates and look at ‘optional’ updates - could be an updated driver for your monitor or vid card is available. Seriously, do not make any changes until this step is proven with pretty high confidence.
Secondly, is the font problem only in your browser, or is it system wide? Desktop icons? documents? Are you on a flat-screen monitor or an old school one?
1)It is system-wide.
2)It's a flat screen monitor.