To me, the best idea for people tied through software to MS products is to use Ubuntu to do their email and surfing chores and then Winblows for the tasks they have to use it for .... offline! That way you get the protection and safety of linux where necessary and then can use MS stuff safely too.

I successfully converted my business computer to Ubuntu about 8 months ago with the exception of Quickbooks. Though there are plenty of linux alternatives available it would have required countless hours of inputting our old data so instead I opted to just keep an old XP machine that lives offline and I use it as necessary to enter financial stuff which works fine