A hole was found in Excel that would allow malicious software to take full or partial control of a machine to alter data or download other malware (define) for installation.
However, in issuing the fix, a problem was introduced. In some cases, files could not be opened in any version of Excel if the executable mode was set to Korean, Chinese, or Japanese when you first created the files. This issue was caused because of the way Excel 2000 processes Asian characters.
Microsoft (Quote) said it has resolved the issue in its re-release of MS07-002 and the problem only, potentially, affects Excel 2000 users. The newer Excel versions in Office XP and Office 2003 are not affected, and it only really applies to anyone using Korean, Chinese, or Japanese executable mode.