rosie123

I had a W in my 3rd year and applied at U of A. They did not ask me about it and it did not seem to affect my application. 

I had 1 W and nobody cared in my interviews, however, it was in first year so it may have been considered less of a big deal since it was earlier on. As mentioned by somebody else, the biggest downside of it was I lost my weighting for U of T. 

The trade-off you may be making dropping the course is losing ability to use weighted wGPA at U of T.    Do you have full course load in years 1-4 ?  If you drop that course you can still apply to U of T but using your cGPA only.   If you keep it,  you can drop 8 half courses from your wGPA.      Review where you will apply and how they treat a full course load.