Option 1. ReCreate the old WAMPServer on the new PC
If you have the complete directory structure backed up from your old PC then you can just copy the complete folder structure from your backup to the new PC.
Make sure you put it on the same disk and folder that it was originally installed on, so if it was originally installed in C:\wamp
make sure you copy it back to that folder.
Launch the wampmanage.exe from that folder ( C:\wamp\wampmanager.exe
)
Using the wampmanager menus do
left click wampmanager -> Apache -> Install Service
left click wampmanager -> MYSQL -> Install Service
WAMPServer should now be as it was before your problem
Windows 8.1 has a blank C:\windows\system32\drivers\etc\hosts
file, so you will also need to add all the domains for any Virtual Hosts you had created, but at a minimum it should have these entries.
127.0.0.1 localhost
::1 localhost
Option 2. Add your old Apache/PHP/MYSQL to the new installation of WAMPServer
Remember, one of the big advantages of WAMPServer over other Windows AMP stacks is its ability to have more than one version of each of Apache/PHP/MYSQL in the same WAMPServer instance ready for easy switching between verions of all of these.
So you could keep the new installation and selectively copy over the Apache/PHP/MYSQL versions and then copy over your 6 sites.
So STOP WAMPServer
copy the OLD \wamp\bin\apache\{apacheversion} folder to NEW `\wamp\bin\apache\
copy the OLD \wamp\bin\php\{phpversion} folder to NEW `\wamp\bin\php\
copy the OLD \wamp\bin\mysql\{mysqversion} folder to NEW `\wamp\bin\mysql\
Restart WAMPServer
You should now see that the old and new version of Apache/MYSQL/PHP are available.
Now copy your OLD \wamp\www\???
site folders into NEW \wamp\www\???
and your 6 sites should also be available.
Now you can switch back to the old versions of Apache/PHP/MYSQL and run your sites like that, or backup you databases properly using the old MYSQL version and then restore them to your new MYSQL version
You switch versions using the wampmanager menus like so:-
wampmanager -> Apache -> Version -> (click the required version number )
wampmanager -> MYSQL -> Version -> (click the required version number )
wampmanager -> PHP -> Version -> (click the required version number )