I have a suspicious Vista box here. Like most boxes like it, it has a bunch of software running on it, including Microsoft Security Essentials. For the past couple months, it's been behaving strangely. It boots up normally and works fine for a few minutes and then sometime (but not always) it enters a strange lock-up state: everything on the screen appears normal, the mouse moves, but if you try to do anything (like open a menu or run a program) the mouse cursor turns from an arrow into a ring and sometimes the screen also goes gray. I can tell it has entered into this state even before trying to do anything, because the HDD activity light comes on and stays on. However, ordinary disk activity on this computer is audible and, though the light is on, we hear no disk activity in this state. If left in this state long enough, the computer spontaneously reboots itself.
When I boot into safe mode (including safe mode with network), it does not lock up. So my working hypothesis is that the culprit must be a program. At first I suspected Skype. I upgraded to the latest version (about a month ago) and the problem seemed to go away, or at least get better, but recently it came back. I uninstalled Skype completely but this time, the problem persisted.
The application that seems to be having problems now is Microsoft Security Essentials. Over the past few weeks, we've been noticing that, occasionally, it will be disabled when the computer boots up. At first I could enable it but now it refuses to be enabled. It says last time updates were downloaded was two days ago but when I tell it to download updates again, it times out. When I tell it to turn on real-time protection, it attempts to do so but fails (time-out). In the grand Microsoft tradition of transparency, the error message is "Microsoft Security Essentials was unable to turn on real-time protection." When I press the "Support Information" button on the error screen, it says: "Error code: 0x800705b4". This is in safe mode.
The last suspicious thing is on boot-up. Right after the BIOS splash, and before "Microsoft Corporation", the screen goes blank and a blinking cursor is displayed at the upper left, for three seconds or so. Then the cursor quickly advances down three lines and immediately thereafter it segues into the "Microsoft Corporation" screen. After that, bootup goes normally.
I have all the data backed up, hopefully, so I can try out any suggestions you might have. Thanks in advance.
When I boot into safe mode (including safe mode with network), it does not lock up. So my working hypothesis is that the culprit must be a program. At first I suspected Skype. I upgraded to the latest version (about a month ago) and the problem seemed to go away, or at least get better, but recently it came back. I uninstalled Skype completely but this time, the problem persisted.
The application that seems to be having problems now is Microsoft Security Essentials. Over the past few weeks, we've been noticing that, occasionally, it will be disabled when the computer boots up. At first I could enable it but now it refuses to be enabled. It says last time updates were downloaded was two days ago but when I tell it to download updates again, it times out. When I tell it to turn on real-time protection, it attempts to do so but fails (time-out). In the grand Microsoft tradition of transparency, the error message is "Microsoft Security Essentials was unable to turn on real-time protection." When I press the "Support Information" button on the error screen, it says: "Error code: 0x800705b4". This is in safe mode.
The last suspicious thing is on boot-up. Right after the BIOS splash, and before "Microsoft Corporation", the screen goes blank and a blinking cursor is displayed at the upper left, for three seconds or so. Then the cursor quickly advances down three lines and immediately thereafter it segues into the "Microsoft Corporation" screen. After that, bootup goes normally.
I have all the data backed up, hopefully, so I can try out any suggestions you might have. Thanks in advance.