Sorry for your loss. You can still file as Married Filing Joint. Go through this Personal Info section, there is a box you can check, that says - Did they pass before filing taxes (something like that).
Just select the filing status on the Name & Address screen in your 1040.com return, then provide your spouse's name, SSN and date of death. And remember, for the year your spouse died, use the married filing joint filing status. Then for two years after, you can use the qualifying widow(er) filing status.
