Seriously, Make Up Your Mind

I am so angry. I worked on a project for another employee at my office yesterday because my boss asked me to. It was ridiculous and I told him that I didn't think the time I would need to spend on the project would be worth the results. He told me to do it anyway. It took me the entire day - working on another person's computer, with a program that crashed every 5 minutes. (That's not an exaggeration.) I finished around 3:45, my boss and this other employee were in a meeting, so at 4:30 I left and went home for the day.

This morning they tell me that the reformatting I did - they're not going to use it. I asked on multiple occasions how much time my boss wanted me to spend on this, each time he told me to keep working. I am angry on so many levels.

1 - This has nothing to do with me and my job.
2 - This employee consistently treats me like his secretary even though I am no such thing.
3 - I am the only person in my department who gets pulled to do this shit.
4 - This shit is not part of my performance goals, so I consistently don't make them.
5 - No one will listen to my side of the story.

Gah! I can not wait to get out of this hell hole today.