I already have Node.js v0.8.0 running on Windows. Can I just run the latest installer to upgrade it to v0.8.4? I am afraid it will break existing third party modules on my machi
Unless you're using a module that relies on an actual bug that was present in 0.8.0 and was fixed by 0.8.4, you're OK. There were no API changes in between those two versions (and the node team is too smart to introduce such changes in a minor release).