Mix salsa, sour cream, taco seasoning, and cream of chicken soup in the bottom of the crockpot.
Add chicken to the crock pot and mix sauce (make sure the sauce is covering the top of the chicken breast).
Cook on low for 8 hours (or on high for 3-4 hours).
Remove chicken from crock pot. Place in a separate container and shred chicken with a fork. I kept the chicken in a separate container and added the sauce on top of the chicken once I was ready to serve. I had a lot of sauce leftover and didn't want to have all sauce and no chicken!