Error when trying to connect using USB script

I have seen the same problem listed in the Internet .
And for me it’s COM3 instead of COM4
Please let me know hw to get over it

first of all, please do not post photos / screenshots instead of copy/pasted text (properly formatted)!

no one will care to struggle to read that photo…

second, this problem is not an “issue or error” related to blynk libs/app, so please do not use this category. (even if the category header is red, will not produce faster / better answers)

Due you have a solution

We don’t have enough information to guess.

Has it ever worked before?

What have you tried so far?

Did you edit any files before running the USB script?

What Operating system are you using?

Are you using an Arduino UNO or something different?

Etc…

Have you followed the full directions?

http://help.blynk.cc/hardware-and-libraries/arduino/usb-serial