Help! Almost new computer keeps freezing randomly.

The difference between gaming and light activity is useful, but it does not prove that the hardware is healthy or that the browser alone is responsible. Continued audio also does not establish which component has stopped responding. First, back up important files and record the exact time of the next freeze. Afterwards, check Windows' Application and System event logs around that time for a named application, display-driver error, or hardware report. Update Windows and the appropriate drivers supplied for your exact computer model. Then use Microsoft's clean-boot procedure to test whether background software is involved, keeping a record of disabled items and restoring normal startup afterwards. Do not change advanced boot settings. Test long enough to cover the usual failure interval. If freezing continues in that controlled state, provide the model, Windows build, and relevant events to the manufacturer, particularly while the machine remains under warranty.