Tip/Solution: One click flashers and "device not found" errors
Putting this in the development thread as I read a lot on these forums about people trying to get one click roots/flashers to work and kept getting a lot of device not found errors, or partially working attempts that ended up failing even though they had the right drivers installed etc.
I never had a problem with this until yesterday and figured out what is going on.
Back story: I normally flashed at home on my main PC and never was an issue but yesterday I got my replacement Epic while at work and had to use my laptop to root, flash clockwork etc. About an hour of errors, unplugging and plugging and devices not found I finally got two to take. It still bugged me what was causing this.
Check your antivirus suite. I personally use Avast. What was happening was Avast On-Access protection was blocking data transfer between my Epic and PC. The device would install fine, appear to be seen by windows but countless attempts to flash, or using the android SDK would result in a blocked transfer within 20 seconds of plugging in the USB making it appear to be dead and "offline" (in the android SDK). It was "there" but data was being blocked.
If you're an avast user and always have these issues try this.
Plug in your Epic.. Right click the blue Avast circle in the Task Tray and click program settings. Next click "exclusions" and then click "browse". Check the empty box for the drive that your Epic appeared as. Mine was "E:". Then click OK out of avast to save it.
Now try flashing, or using the Android SDK. It should work flawlessly now without any out of no where device no found, offline errors.
Other AV users: Disable the entire thing during one click flashers