WEIGHING SCALE???

Hello Experts,
I belive that this also lies in the IT Depertment. So if any one of you know how to solve this issue.please help.
I work in a Horticulture company so we do a lot of weighing of products on weighing scale then the weight is relayed in computer via the MuddyBoot Software.
Now the problem is; when the workers try to weigh the goods from the copmuter, it brings an Error: Access denied to the Port COM1. Now they have to do it manually. Please Advice on what to do if you have an Idea.