If you will be re-installing the same version of perl as you are currently running, then backup and restore of the perl library may work.

You should re-install perl itself so its libraries are registered, file associations are set up, etc. If any of the packages you have installed are not pure perl then you may have to re-install them also, or otherwise reproduce whatever was setup at install time other than the files in the perl directory (registering dlls, file associations or whatever).

If you will be installing a different version of perl then the risk of faults will be greater, particularly if you have installed packages that are not pure perl.