This can be happen when new OS has been installed..Apache needs this dll file
So just we have to download the files
I am using win 7 home basic 64 bit(x64)
so here is the link:
https://www.microsoft.com/en-us/download/details.aspx?id=13523
https://www.microsoft.com/en-us/download/confirmation.aspx?id=30679
http://www.microsoft.com/en-US/download/details.aspx?id=15336
Just download those files and then install and open WAMP ..It will run smoothly without any kinds of errors 🙂