Hard lesson I've learned about IE11, keep adobe flash up to date as fast as they push a new update out. If you notice IE running slow or acting strange, and you keep your cache and history cleared out, check to see if adobe just released a new update for flash. I've had pages at sites I visit go from a crawl to light speed by updating flash. Then over the next month crawl again and suddenly a new update is available at adobe.
If you watch a lot of content at hulu or other sites like it on your PC. And you start getting timeouts that your internet connection cannot be the source of. See if there is a new flash update.
Krapola, krapelleii, krapula........