Avrdude: ser_open(): can't open device "\\.\COM28": Access is denied

Hello. I tried to use again Arduino Uno and encountered problem as indicated in the topic session of this issue. So basically, I tried to load a sample code to Arduino IDE and got the error, having a prior knowledge with Arduino, I knew instantly what the problem was all about. So checked everything from ports, board, drivers and then looked for an available ports of my laptop because even in the internet it will tell you that one way to solve it is to look for another port, so I did. So from COM4, I transferred to COM 7, COM 10, COM 17 and now COM 28(as reflected in the topic) numerous times because they were the available ports sometimes, but to my surprise, I've still been getting same error. I tried to reinstall the software more than 5 times, reset the board and restart my laptop several times yet NONE OF THEM EVER WORKED. I've been trying to solve this problem since yesterday and it's been tiring and frustrating. I hope somebody could shed some light on this issue because it's really driving me crazy already. Thank you!