continuos scrolling

I have complaints from several staff memebers that when they left click on a scroll button, then let go, their screen continues to scroll.

I have applied the IE smooth scrolling setting and it does not help.

Microsoft suggests:
Using RegistryEditor, remove the m_exec.exe string value from the following registry key:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run

HOWEVER, this key does not exist.

Please repply ASAP.

Thanks.