There are a number of things that can go wrong with a scroll bar on Internet Explorer, particularly if you have recently installed a new version of the software. The scroll bar may not scroll smoothly, arrows or parts of the bar can disappear, or the bar may "stick." There are several problems that can cause all of these issues.
Interference From Add-Ons
One cause of scroll bar performance problems may be that your browser add-ons, such as toolbars and browser extensions, are affecting the program's performance. To fix this, click the "Tools" drop-down menu. Click "Manage Add-ons," make adjustments, and try operating the program while some or all of your add-ons are disabled.
Drivers Not Current
Another possible cause for scroll bar performance problems is that all of your drivers are not up to date and are affecting the program's performance. Update all of your drivers, particularly the mouse and video drivers through Windows Update or the manufacturers' websites.
Background Program Interference
The root of the problem may be in another program running on your machine that is interfering with Internet Explorer's performance. Restart your computer in "Safe Mode" by pressing "F8" while it is starting. If the problem is resolved in Safe Mode, perform a "clean boot" and launch Windows with minimal functioning drivers to determine the exact source of the problem and resolve it. If you can isolate the program creating a problem, contact that program's manufacturer to fix it.
Screen Resolution Too Low
Some scroll bar problems might be the result of low screen resolution. It should be 1024 by 768 pixels or higher. Right-click on the desktop in Windows XP or Windows Vista and adjust screen settings on the "Personalize" or "Properties" tab. In Windows 7, click "Start," type "Resolution" in the Search box and select the desired resolution.
There could be a number of other scroll bar performance problems related to malfunctions in your Windows operating system or Internet Explorer. Make sure that Windows and all Microsoft programs are up to date through Windows Update. Also try uninstalling and reinstalling Internet Explorer. If there is still a problem, run the Windows Troubleshooter through the "Help and Support" tab on the Start menu to see if it can detect any problems. If all else fails, contact Microsoft Support.