Recently i came across this js dependency manager bower. However it requires both node and npm to be installed.
1) Just wondering if there are side effects to installing node. For example cpu and memory usage. And are there upsides to it other than bower?
2) Is there a way i can turn off the node service when im not using it.
3) In addition, been looking around and cant seem to find a bower like solution that runs natively on windows
Bower is now considered as an obsolete package manager, and the general advice is to use npm package registry (which is by default in npm). I don't even think that there are packages which are bower exclusively. There are different package managers, but they use npm registry too (like yarn, for instance).
Regarding your questions:
2) No need to.
3) Almost all package managers (including bower) work on Windows good. Actually, almost all JS ecosystem now works quite good and stable on Windows.