Help me UNO

Dear All,

In my arduino UNO, last uploaded program run when connect pc or power supply (9V). but this is not detect on pc. How can I fix this problem.

Best Regard, Prince

What else is connected to the Arduino?

It is not detected (ie, no com port) or you get a COM port and can't upload to it?

In the latter case, please post the error.

DrAzzy: It is not detected (ie, no com port) or you get a COM port and can't upload to it?

In the latter case, please post the error.

I have had the former happen several times. Online it says to check drivers, I have found that it is easier to just uninstall then reinstall Arduino.