It's a bug in the latest version of chrome. You can either reset chrome (will lose all of your data such as passwords, history etc) which may not work or install this extension. https://chrome.google.com/webstore/detail/win7-scrollbars/cifcnoebhbpdndjendfkpehpfbglgfkc
Good luck,
Tom
Excellent mate thank you very much, ill give them a go .
It's okay! Report back with how you get on!
All the info is in here https://support.google.com/chrome/answer/3296214?hl=en-GB