Computer is slow when Windows Photo Gallery displays TIFF images that do not fit into one page in Windows Vista

Note If you would rather fix this problem yourself, go to the "Let me fix it myself" section.

When you use Windows Photo Gallery to view TIFF images that do not fit into one page in Windows Vista, the system performance is slow.

To determine the file type of an image, go to the "How to determine the file type of an image" section.

Immediately after the first in a series of images has finished displaying on the screen, Windows Photo Gallery loads the next image. This process is also known as precaching. If the next image is a multipage TIFF file, Windows Photo Gallery processes the complete file. This process may take a while and use too many system resources, depending on the size of the TIFF file. This behavior causes slow system performance and a significant increase in the memory usage of the computer.

To determine the type of the image file, use one of the following methods:

1. Right-click the image file, and then click Properties. In the General tab, you can find Type of file.
2. Uncheck the "Hide extensions for known file types" option in the View tab after you double click Folder Options in the Control Panel. This displays the file type of all files.

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:

To fix this problem, you have to disable precaching in Windows Photo Gallery. To do this, follow these steps:

1. Click Start, click Run, type regedit, and then click OK.
   
   Note If you are prompted for an administrator password or for confirmation, type your password, or click Continue.
2. Locate and then click the following registry subkey:
   HKEY_CURRENT_USER\Software\Microsoft\Windows Photo Gallery\Viewer
3. On the Edit menu, point to New, and then click DWORD Value.
4. Type CacheSize, and then press ENTER.
5. Right-click CacheSize, click Modify, type 0 in the Value data box, and then click OK.
6. Exit Registry Editor.

Click here to understand how the MATS package works to fix this problem