I purchased a Dell Dimension Desktop E521 roughly 3 weeks ago. It came pre-installed with Windows Vista Premium Home. The computer runs well when its working, however the biggest problems I have with Dell and Vista is the hibernation/sleep/power saver mode that occurs when you leave your computer on for an extended period of time. Since I received the computer in the mail every 3 hrs of no activity, the computer goes into a power-saver mode (I'm unsure of what it is really doing). Once it goes into this mode the only way to return service to the computer is via a hard reset. I spent several hours on the phone with Dell Technical support trying to resolve the issue, doing tests that ranged from checking the hard drive for problems (none found) to several system restores with the same problem still occurring. Finally I had their Technical manager tell me that its windows vista design to have you hard reset the computer when in this state. That the computer is meant to work this way. I'm very displeased with the response I have been given and they have no answer as to why its behaving this way. Ive installed all the latest updates for Windows Vista, all the drivers are up to date with the latest versions. Still the computer has the same problem. Has anyone else had a similar problem? I have the AMD 64x2 3800 processor with the AMD Radeon 1300 pro video card. The symptoms I am experiencing when this happens are as follows: Orange light on monitor with black (no display) screen or a blue screen with vertical bars. No error messages. Keyboard lights don't work, mouse doesn't move. Power light on computer is solid green (no activity). Pressing any key on keyboard or moving mouse does nothing. (No beeps) Only way to resolve the problem is to hold the power button for roughly 5 seconds and do a hard reset. Windows then detects an improper shutdown and prompts to go to a fix mode that finds no errors and has no idea what caused the failure.