Question : Problem: COM port keeps having a problem

My company has a HP dc5700 attached to a label printer and a pharmacy pill packing machine. The printer and packer are attached to a A/b switch with serial connections. The switch connects to the serial port on the computer (COM1). The programs being used only print out to COM1.  
 Now for the problem, every now and then I will get a call saying they can not print, the program is saying it cannot print to COM1.  I go to the computer and delete the COM1 port from the device manager. Everything will print fine after deleting and redetecting the com port.  
   Can someone think of way to prevent this from happening , or why it would be happening, a possible permanent fix, other than me replacing the computer, or reinstalling windows.  

Answer : Problem: COM port keeps having a problem

does the software use direcly the com port or prints to a windows serial printer, because if it prints directly to the port, in windows xp or 2000, you cannot have any printer instaled and redirected to a serial port, if you have, delete these printers, because they are reserving the port, and that's why doesnt print. put the software printing directly to the port without using any windows printer. check also if the port speed is the same as the printer controler.