After leaving MS-Windows for good I had a hell of a time doing taxes. H&R Block online almost worked, but gave me problems AND wanted to charge more for processing my K-1.
Then I found TaxAct.com -- The best experience I've had doing taxes for the third year running. They are cheap and flawless even on Linux. Don't forget to whitelist the domain on any AdBlocker or ScriptBlocker you may use.
I absolutely recommend TaxAct.com.