Why does Internet Explorer hang when it accesses Temporary Internet files (disk cache)?

A. Internet Explorer (IE) can enter a state where it almost immediately hangs and starts to use 100 percent of CPU time. In particular, trying to delete Temporary Internet files via Tools, Internet Options triggers this behavior. Also, all attempts to delete files or folders from %systemdrive%Documents and Settings%username%Local SettingsTemporary Internet Files (or wherever the Temporary Internet files folder is located) causes Windows Explorer to hang. This behavior occurs because the Temporary Internet files database is corrupt.

The Temporary Internet files aren't really files but entries in %systemdrive%Documents and Settings%username%Local SettingsTemporary Internet FilesContent.IE5index.dat. Deleting that file solves the problem.