I would advise using Ubuntu. It has Libre software (which is comparable to Microsoft Office) and its less likely to get viruses. But if you must use Windows for something (like games), don’t ever surf the net with it.
Unfortunately, the brokerages and other business related service almost always refuse to use Linux or other non-Microsoft operating systems. So, you have to go online with a Microsoft Windows system and all of those vulnerable services which cannot be turned off because they are necessary for the applications being used.
There are a few brokerages and banks that support Linux type clients, but they are few and typically not the businesses you need to access. Apple is not much better and is getting more vulnerable as the iPhone and tablets become more common inusage.