How to toggle Scroll Lock in Excel 2010 without a Scroll Lock key in the keyboard

It's 'Fn' + 'S', accidentally pressed instead of 'Ctrl' + 'S', which is the toggle shortcut on my Dell - and most Dells, in general.

Also, 'Fn' + 'C' works for HP Elitebook laptops. Try if it works for you.

From this link which refers to the Excel help file:

"If your keyboard does not have a Scroll Lock key, on your computer, got to Start, All Programs, Accessories, Ease of Access, and then click On-Screen Keyboard. When the on-screen keyboard appears on your screen, click the slk button."

There is a picture of this process at the link.

On an HP Probook 440, function + C locks and unlocks ScrLk.