Wampserver is a fancy name for a kit of parts for Windows consisting of Apache, MySQL, PHP, hence the name WAMP.
So, to see if MySQL (the bit we can help with) is working, take alook at the services to see if MySQL is running.
Start | Run "services.msc"
Is MySQL listed? Is it running?
If it's running, can you login with mysql command line client?
Open a command line (a.k.a. a DOS prompt).
CD to the folder MySQL is installed into. The MySQL standard is C:\Program Files\MySQL\MySQL Server 5.x\bin.
It could be differnt on your machine, you'll need to find it.
now start command line.
C:\Program Files\MySQL\MySQL Server 5.x\bin\>mysql -uroot -p
Enter the root password you set when you installed. If you didn't set a root password then leave it blank and press enter. Do get a welcome message?
Now, show databases
mysql>SHOW DATABASES;
When you did a system restore, it didn't remove the mysql database(s). Un-installing MySQL (wampserver) doesn't remove the database(s). When you re-install it doesn't overwrite any existing database, so any usernames/passwords are retained from old installion to to new or re-installation.
Good luck,
Barry.