about SerialPortReader

So,I'm already finished my OV7670's circuit and tried it using SerialPortReader but I got an error. The error said,"Access to the port 'COM4' is denied". What should I do?

Do you have COM4 open in any other application? Serial ports can only be open in one application at a time.

No. Only in SerialPortReader. Firstly, the pic didn't came out. So,I stopped it. Then,started it again. After that,the error message came out.

What is SerialPortReader?

Stopping a badly written application might not release the port; did you try a reboot?

SerialPortReader look like a software only for OV7670 to me. And,can you explain about the reboot?

The reboot that I suggested is a PC reboot (I assumed that SerualPortReader runs on a PC).