Hi,
It is not possible to have two versions of Wampserver on the same PC.
Before installing version 3.3.0, it is imperative to remove the wampapache(64) and wampmysld(64) services from version 2.2 before uninstalling version 2.2, of course having backed up your local sites and related databases.
You should also remember to empty your browser's cache from time to time.
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Documentation Apache -
Documentation PHP -
Documentation MySQL -
Wampserver install files & addons