Using Windows XP SP3, USB1.x, CCleaner Registry, USBDeview. I have been trying for a week to update the phone from CJ05 to 2.1. "USB device not recognized" is the message when the phone is put in Download mode and connected to laptop. I have deleted all Samsung/Android drivers and used the installer (tried both CL14 and 2.1). Using CCleaner Registry tool, I noticed that the installer copies C:\Program Files\Common Files\Samsung_Mobile_USB_Driver(V5.2)_V1.2.1060.0.exe and deletes it at the end, and claims successful installation. I overcame this by quickly copying the file and pasting it back after the installation process. However, I don't know if this matters, but the following three issues still appear after installer completes: => Unused File Extension .tar HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.tar => Old Start Menu key Phone Flash HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MenuOrder\Start Menu2\Programs\Phone Flash => Old Start Menu key Samsung HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\MenuOrder\Start Menu2\Programs\Phone Flash\Samsung The menu entries do exist in Start Menu, don't know what is Start Menu2. Also, I have been unable to delete some Android entries in the registry even after uninstalling all Samsung/Android software. Wondering anyone with deeper knowledge of Windows XP SP3 Registry could help.