A hard reset removes all information from your device and returns it to a state just like it has never been used before. All contacts, messages, emails, third-party applications, etc. will need to be reinstalled after performing a hard reset. To perform a hard reset, from the Home screen tap Menu > Settings > Privacy > Factory data reset. Follow the on-screen prompts to complete. This process will take 5–10 minutes
My Evo got the OTA upgrade last night, and now my settings lack a "Privacy" section. How do I factory rest the phone now?
I installed the bootleg Flash 10.1 on Eclair, and now I find it conflicts with the factory installed Flash on Froyo to the extent of causing the browser to crash frequently. Consensus on the forums is that a factory reset is required to fix this.
I did a factory reset. It was a bit painful, but it was the only solution I found on the boards that offered a permanent fix. I didn't try it, but it was reported that reloading the Flash hack package would fix things until your next restart. I wanted the change to stick however, and I also wanted Froyo's standard code. You might try searching android forums to see if there's not another fix out there. It may just be a couple of files with incompatible configuration info, or it could be more extensive than that.
Check out a fun infographic that teaches you how to increase storage, enhance security, improve battery life and clean your device.