Office 2003 with SP3 won't open my files
Lately some PowerPoint 2003 users have been unable to open some older file types due to changes introduced in Service Pack 3 (SP3) for Office 2003.
This Microsoft Knowledgebase article describes the problem and suggests some fixes that involve making registry changes. The article includes links to REG files that solve the problems described.
If you aleady understand what to do with REG files and would like to download them directly: