Steps to take before installing (recommended) Hard Disk: HFS+ hard disk format (also known as Mac OS Extended or HFS Plus).Operating System: Mac OS X version 10.4.9 or later.Processor: A Mac computer with an Intel, PowerPC G5, or PowerPC G4 (500 MHz or faster) processor.To run Microsoft® Office 2008 for Mac, your computer must meet the following requirements: 5.5 Opening documents created with very old versions of office.5.3 Can't send meeting invitations (error -17997).5.2 Word, Excel, PowerPoint, Entourage 2008 are slow when opened the first time after a reboot.4.5.3 Save and Move - add missing buttons.4.5.2 Fonts, spelling, attachments options.4.5 Recommended tweaks for Microsoft Entourage.4.4 Recommended tweaks for Microsoft Excel.4.3 Recommended tweaks for Microsoft PowerPoint.