when I try to upload the sketch, this showed up and won't upload onto the Arduino.
this is what it says:
Sketch uses 936 bytes (2%) of program storage space. Maximum is 32256 bytes.
Global variables use 9 bytes (0%) of dynamic memory, leaving 2039 bytes for local variables. Maximum is 2048 bytes.
avrdude: ser_open(): can't open device "\.\COM4": The system cannot find the file specified.
Failed uploading: uploading error: exit status 1
Hello, welcome to the forum!
I think you're new because it says you've joined 7 minutes ago,
you might want to read this if you haven't already!
as for your issue,
please disconnect everything from your Arduino and try again. see if this works.
So we know that you're using windows
and probably a 328P based board (which one?).
What does Windows device manager think of your board? Is it indeed COM4? Any yellow exclamation marks? Does COM4 disappear from Windows device manager and the IDE when you disconnect the board?
Ensure your USB cable is a DATA cable and not a RECHARGING cable.
Genuine or clone Arduino ?
Try to select the port which your arduino is connected to. If that doesn't work try to hold the reset button while it is saying "compiling sketch" and when it reports memory usage
release it. Try that a few times if you don't get the timing right it won't work.
Good luck!