How can i reinstall android 4.4 in Samsung galaxy s2 GT1900. when i turn on on logo appear and off automatically. I try odin but it cannot scan id com .
When you connect your device via USB, a windows popup should appear and telling you that it is installing some samsung drivers. In linux, you can use lsusb to check if you device is recognized.
If odin is not seeing you device, I think either your charger cable is damaged or you should use another USB port, I would suggest an USB2 port directly at the PC.