It's ridiculously simple: cost. Pre-installing the full blown MS Office would add a LOT to the cost. Office 2010 Pro (the not so "limited" version, although that still doesn't include Visio nor Project) would add $300 to the cost of a new PC which is basically as much as some PCs go for these days. How funny! Actually there is a new Office product out there (well it hit with the rest of Office 2010 RTM) called Office Starter. Basically, an OEM can install a trial of Office 2010 Pro on a system. You get three options: 1. Purchase a real version of Office online 2. Use a product key to unlock a particular Office version 3. Install Office Starter, which includes a free (but limited) version of Word and Excel. To my knowledge, the Starter install does not expire. If Starter is installed, you get 2010 Pro for 60 days, and after that, you can only use the Starter apps. http://office.microsoft.com/en-us/starter/ Now, the task of getting it pre-installed on every computer is left up to the OEM. Some have done it already.