Dreamweaver uses Javascript to help some of the program's functionality. I came across this issue a couple of years ago, and it was related to an update that didn't install correctly (I think due to my antivirus software).

I ended up uninstalling Dreamweaver, reinstalling it and then ignoring any updates. I tend to do the same with most Adobe software, and only install the recommended updates if they're absolutely necessary i.e. fix a serious security bug or provide new functionality that I need. Otherwise I kept finding Dreamweaver etc. would run slower and slower with each update.