Hello, I am assuming you are talking about telemetry: * Go to Tools (or [[Image: New Fx Menu]]) > Options > Advanced > Data Choices * Uncheck the boxes you don't want, or click Learn More to see what it is used for These shouldn't slow down your browsing experience too much, if at all, so please take a look at the articles [[Firefox is slow - How to make it faster]] and/or [[Firefox uses too many CPU resources - How to fix]] if you are still experiencing problems, or post back with more information about when/what you are doing when Firefox slows down.