After all, several missions are time or progression-sensitive, so those are easy to fail if you're not careful. However, there are some risks to embarking on some adventures at the wrong time. You need to do nearly all of the Priority quests in a set sequence, but you have more control over when you play each secondary operation. MORE INFORMATION IS AVAILABLE AT not being as open as its predecessor, Mass Effect 3 gives you plenty of freedom regarding mission order.
For users with User Account Control enabled, launch Steam using the “Run as Administrator” option or launch from the windows shortcut. If the User Account Control feature of Windows Vista is enabled, launching “Mass Effect” from Steam will result in failure.
* WINDOWS VISTA OR WINDOWS 7 USERS: Launching “Mass Effect” from Steam requires the setting “Run as Administrator”.
Hard Drive: 12.0 GB or more free hard drive space.Graphics: DirectX 9.0c compatible, ATI X1300 XT or greater (ATI X1300, X1300 Pro, X1600 Pro, Radeon 2600 HD, and HD 2400 are below minimum system requirements) NVidia GeForce 6800 or greater (7300, 7600 GS, 8500 are below minimum system requirements).