Glitch in Excel and Word

Hello,
I've got a problem with Excel and Word in Office 97. In Excel with I tab from one cell to the next, it closes Excel and goes right to the desktop. Same with Word. If I've take the cursor to the bottom task bar, it closes Word and goes to the the destop and all work is lost. The computer also has Open Office on it and it works just fine. I'm just not used to using it and therefore, prefer Office. But not if it's going to keep doing this.

Any suggestions?

Thanks in advance.