|If it was just adding the ram that did it I would assume the additional ram is using resources that previously were used by the com port and/or the foot pedal.|
Do any problems show in device manager?
You may be able to change the com port settings. In cmos/bios setup if you have an option for 'PnP OS', enable that. That allows windows to configure some of the hardware that's normally done by the bios. The com port will probably have some preset configurations and maybe something like 'auto'. Set to auto if possible.
Uninstalling and then reinstalling the foot pedal software may be necessary after the changes. Or you may be able to configure it from within the software.
I all else fails I guess you can remove the ram you installed .
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