avrdude: ser_open(): can't open device "\.\COM4": Access is denied. Failed uploading: uploading error: exit status 1
What to do???
Which board? Clone or original?
Did it ever work before?
Is COM4 your board? Does it disappear when you disconnect?
Which Windows version?
Which version of the IDE?
Anything that might be using COM4?
If you have bluetooth enabled, switch it off and see if that helps.
If you have an antivirus installed, temporarily disable your antivirus and see if it helps.
Access is denied
Kind of tips me off... that you don't have the permission to access that port...
Sorry not a windows person ... you need to set read/write permissions on the port...
Good luck
I am really depressed in Arduino Pro mini and my laptop .
I am uploading sometimes a sketch property but most of the time it keeps saying ser_open(): can't open device "\.\COMX": Access denied.
It is a university laptop which means I cannot access it as an administrator but only as a user under my profile. Which means I cannot change anything on port name etc. What else I could try or at least seek solution on?
I have merged your cross-posts @anon58303660 .
Cross-posting is against the Arduino forum rules. The reason is that duplicate posts can waste the time of the people trying to help. Someone might spend a lot of time investigating and writing a detailed answer on one topic, without knowing that someone else already did the same in the other topic.
Repeated cross-posting can result in a suspension from the forum.
In the future, please only create one topic for each distinct subject matter. This is basic forum etiquette, as explained in the "How to get the best out of this forum" guide. It contains a lot of other useful information. Please read it.
Thanks in advance for your cooperation.
You could try the things mentioned by the people who tried to help you when you posted about it 10 days ago and never responded.
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Well thanks for the information shared; however nothing helped from the previous post and therefore I created a new one hoping that more members would be able to view and help.
In any case I managed to solve the issue but no based on any recommendation given here. I believe that the aim of the forum is not to warn / suspend users but help them!
As I already explained, that is against the rules. You should have replied here to say what you tried and the results you got from doing that. The helpers would have then quickly followed up with additional advice. It is often necessary to iterate through multiple of those feedback cycles before a problem is resolved here.
You are correct that the purpose of the forum is to help people by sharing knowledge.
In that spirit, please take the time to post here a summary of the solution you found. I'm sure others who have the same problem and find this thread during their research will be very grateful.
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Sure.
Finally it was issue on windows permission on accessing the port. So what I did is to change the name of the port and grant access to the local user as there were two profiles on the pc (administrator and local user).
I have actually assigned solution now to jkwilborn as I think that this was the closest answer (including changing the name of the port... for some reason this was required also)
As I stated... not a windows person... 
Glad you're back running again... have fun
Take care and good luck
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