How detrimental is a "W" on a transcript?

I'm not sure how a W (withdrawal) deeply effects the decision from a grad school admissions officer but it has to be a great deal better then getting an E on ones transcript.

What is your college's deadline for withdrawing from a class? I'd assume that if you're hitting midterms then perhaps its a bit too late. But even if you are able to withdraw, don't make a habit of it with future courses. I think that one W on ones transcript might be overlooked. But making a habit out of the practice will be picked up by any admissions officer in reviewing your grad school application.

I have ~9 weeks after the class starts to drop it with a W on the transcript. It's only been ~6 weeks. I can take this class this summer, or 2013 summer time. So based on today's exam, I'll see.

21 credits?
I think it's safe to say that it's a good idea to just stick to 18 credits a semester, especially if you're also doing part time work.

As the above poster told you, a W on a transcript is better than a Fail.
As long as there isn't a recurring patterns of W on your transcript, you won't be scrutinized when the time comes for you to apply to grad schools.

I know a person who had 5 "W" in a semester because she had to drop out due to health reasons. Due to a valid reason behind the sequential with-drawls, it didn't effect her chances of entering medical school.

Good Luck on that midterm.

I'm sure that if anyone questioned you, the excuse that you bit off more than you could chew, realized your mistake and cut back appropriately would go over very well. I don't see any issues.