MySQL incredibly slow on WAMP and XAMPP

I've installed WAMP on my new Windows 8 machine and for some reason when I use PHPMyAdmin to import an sql file (it's only about 5mb), it takes several minutes before timing out. And then when I check I can see it's only imported a fraction of the tables. I've tried other sql files and it's the same story. These same sql files import perfectly fine (and in a few couple of seconds) on my Windows 7 machine also running WAMP. I've since uninstalled WAMP and tried XAMPP, and the problem still exists. Even just browsing the databases with PHPMyAdmin takes a long time between page loads. I am guessing it's a problem with MySQL. Any suggestions would be helpful.