I'm not certain this is the right place to ask, but I've seen other Arduino threads on stackoverflow, so I just assume it's ok.
My arduino uno-compatible board is not getting recognized. I tried it on windows 8 and on windows xp. When I open the device managers, there is just one entry called 'USB serial port' under the 'Ports (COM & LPT)' section. The Arduino, however, does blink when connected.
I tried uninstalling the usb serial port drivers, or updating them, but both don't work: the drivers seem to be up to date and when I uninstall and reconnect the arduino, they appear again.
When I try to upload a program I get
avrdude: stk500_getsync(): not in sync: resp=0x00
or
avrdude: usbdev_open(): did not find any USB device "usb"
(when I use 'upload using programmer').
I hope anyone can help me with this, I've been trying to get it to work now for quite some time.
EDIT 2: I tried the same thing at my parents' computer, which has windows vista installed. There, the board gets recognized as a USB serial port under 'Unknown devices' (first as something else, I think it was a code with two uppercase letters and then four digits, but I'm not sure and I can't get that name back, even after uninstalling the drivers).
Did you install the drivers? See the Arduino installation instructions under #4. If you are trying with Windows 8 there are some other steps involved.
There is an Arduino UNO instructional video that shows how to install the drivers. The following url should start you at the part where the instructor talks about manually installing the driver.
http://www.youtube.com/watch?feature=player_detailpage&v=kLd_JyvKV4Y&t=1140
I ultimately got it working using the Arduino Enchanched Release for Windows. That installed the right drivers for me. Then I had to choose the Duemilanov board (while the actual board is a 'Uno'). I think I tried that board before, but apperently I didn't have the right drivers installed at that time.