The Old New Thing

What does an NMI error mean? (The infamous "Hardware Malfunction")

I promised to talk more about NMI, so here it is. What generates an NMI? What does it mean? The first question is easy to answer but doesn't actually shed much light: Any device can pull the NMI line, and that will generate a non-maskable interrupt. Back in the Windows 95 days, a few really cool people had taken the ball-point pen ...

How to get your laptop to resume from standby in under two seconds

One of my colleagues recently posted the story of the work he did to get laptops to resume quickly. The fun part was implementing the optimizations in the kernel. The not-fun part was finding all the drivers who did bad things and harassing their owners into fixing the bugs. One some laptops, he could get the resume time down to an ...

The undeletable Outlook folder, episode 2

I had another undeletable Outlook folder, and all my tricks for cajoling Outlook into letting me delete it failed. I already deleted all the items in it, emptied it of offline items, deleted all the failures from my Sync Issues folder, but still I couldn't delete the folder. But I came up with a new trick. I moved the folder out of its ...

How do I find all files with at least one space in their name?

You already know how to do this, you just don't realize it. How do you find files with an "x" in their name? That's right, you use . Now you just have to change that x to a space. And since spaces are command line delimiters, you need to quote the sequence so it gets treated as a single parameter rather than two "*" parameters: Stick ...

Placebo setting: QoS bandwidth reservation

A placebo setting that has been getting a lot of play in recent years is that of QoS bandwidth reservation. The setting in question sets a maximum amount of bandwidth that can be reserved for QoS. I guess one thing people forgot to notice is the word "maximum". It doesn't set the amount of reserved bandwidth, just the maximum. Changing the ...

The window manager moves the mouse; applications choose the cursor

You can sometimes narrow down the source of a problem just by looking at the screen and moving the mouse. When you move the mouse, the cursor on the screen moves to match. This work is done in the window manager in kernel mode. The mouse hardware notifies the window manager, "Hey, I moved left twenty units." The window manager takes this ...

Why can't I get my program to use more than 50% of the CPU?

This is sort of the reverse of Why is my CPU usage hovering at 50%?, but the answer is the same. When I run a CPU-intensive task, the CPU percentage used by that process never goes above 50%, and the rest is reported as idle. Is there some setting that I set inadvertently which is preventing the program from using more than half of the CPU...

Offline mode silently prevents you from streaming media content

Into Windows Media Player (version 9 if you're keeping score at home), I type the URL of an MP3 file (poor man's podcast) and get the error message "The download of the specified resource has failed." On this dialog there two buttons: Close and Web Help. Close closes the error dialog, of course. Web Help does nothing. Turns out the real...

How do I shut down a workstation via Remote Desktop?

When you are connected to a workstation via Remote Desktop, the "Turn Off Computer" option changes to "Disconnect". But what if you really want to turn off the computer, hibernate it, or put it on stand-by? Note: These tips work on Windows XP, but there is no guarantee that they will work in future versions of Windows. One way to do ...