Hi,
This means that the file C:\Windows\System32\drivers\etc\hosts is blocked by your anti-virus or anti-spyware software.
Put this file as an exception in your anti-virus and/or anti-spyware software.
In addition, it would be necessary to read and apply item 09 of
TROUBLESHOOTING TIPS---------------------------------------------------------------
Documentation Apache -
Documentation PHP -
Documentation MySQL -
Wampserver install files & addons