Hi,
I don't have 3.1.3 full install but 3.1.3 update is available here:
https://wampserver.aviatechno.net/files/updates/wampserver3_x86_x64_update3.1.3.exeyou can reinstall the 3.1.3 update without any problem.
If MySQL still doesn't start, try:
- Left-Click -> Restart Services
- Right-Click -> Tools -> Reinstall all services if this option exists.
---------------------------------------------------------------
Documentation Apache -
Documentation PHP -
Documentation MySQL -
Wampserver install files & addons