Input queues

What to do

1. Open w0a
2. Go to the Fix page in the left menu
3. Type girdi into the search box
4. Press the button on the Input queues card

What the card's answer means

After you press it, the card writes a line underneath. Which line you get decides your next step.

• "Fixed — N setting(s) put back to the Windows default." — this was the broken thing and it has been put back. If the problem continues, see below.
• "Nothing to fix — this was already at the Windows default." — these settings were never changed. Whatever you are seeing has another cause, and pressing this card again will not help.
• "Nothing to fix — this component is not installed on this PC." — the thing this card repairs is not present on this Windows. Your edition may not include it, or it may have been removed earlier.
• "Another repair is running." — only one card runs at a time, because several of them would undo each other's work. Wait for it to finish and press again.

What this card actually does

If a key press or a mouse movement occasionally does not register at all, restores the driver queue sizes to the Windows defaults. Writes 100 to the class drivers and deletes the values at the HID layer below them, where a clean Windows writes nothing at all. Needs a restart.

Every repair card writes back the Windows default unconditionally; it does not depend on a backup of w0a's own existing. So it also helps if some other tool was what changed your machine.

The values it writes and deletes:

• HKLM\SYSTEM\CurrentControlSet\Services\mouclass\Parameters\MouseDataQueueSize = 100
• HKLM\SYSTEM\CurrentControlSet\Services\kbdclass\Parameters\KeyboardDataQueueSize = 100
• ...\Services\mouhid\Parameters\MouseDataQueueSize — deleted
• ...\Services\kbdhid\Parameters\KeyboardDataQueueSize — deleted

Why the two halves differ: 100 is the class drivers' documented default. The HID layer below them carries a value of the same name, but a clean Windows writes nothing there — so those two are deleted rather than set to 100. "Restoring the default" of a value that does not exist would mean creating it.

A queue is not a latency setting. Making it bigger does not deliver a report sooner and making it smaller does not delay one; the queue is only the buffer between the driver and the thread reading it. A small queue drops reports when that thread stalls for a moment — on an 8000 Hz mouse that takes a few milliseconds.

The change is read when the driver loads, so it does not take effect until you restart.

If it did not help

If the card said it fixed something and the problem is still there, these settings were not the cause. Write to us — tell us which card you ran and what it printed; the two together are what narrows it down.