Edit - Super User

You are not logged in. Your edit will be placed in a queue until it is peer reviewed.

We welcome edits that make the post easier to understand and more valuable for readers. Because community members review edits, please try to make the post substantially better than how you found it, for example, by fixing grammar or adding additional resources and hyperlinks.

Thanks. Currently the two computers are not connected to the network at all, so Firewall settings can't be the cause.
– Roee Adler
Commented Nov 15, 2009 at 13:16
So the cause is installed software that causes the very lousy XP internal clock to lose time, which is only normal, no worry. To sync time, you'll need to network both computers and set one as the time server of the other.
– harrymc
Commented Nov 15, 2009 at 13:54
There is no such thing as "processes stealing idle CPU cycles", and updating the time does not depend on process-based or even thread-based code, nor on "idle CPU cycles" being available. It happens in the interrupt handler for the interval timer (from memory, the routine name is KeUpdateSystemTime). These interrupts are handled at IRQL CLOCK_LEVEL, ie 24 on x86. This is higher than any ordinary I/O device interrupt, let alone process-based code. Something else is going on.
– Jamie Hanrahan
Commented Jan 21, 2019 at 23:10
@JamieHanrahan: The stealing could involve other interrupts.
– harrymc
Commented Jan 22, 2019 at 7:55
"Other interrupts" wouldn't involve background processes, and the only interrupts of higher IRQL than CLOCK_LEVEL aren't associated with things that occur with any frequency, nor with I/O initiated by processes. So it is wildly unlikely that process-based activity is going to slow down the clock. It's completely unclear to me how the mechanism you describe could occur. Can you explain your idea further?
– Jamie Hanrahan
Commented Jan 22, 2019 at 8:35

| Show 2 more comments

Correct minor typos or mistakes
Clarify meaning without changing it
Add related resources or links
Always respect the author’s intent
Don’t use edits to reply to the author

create code fences with backticks ` or tildes ~
```
like so
```
add language identifier to highlight code
```python
def function(foo):
print(foo)
```
put returns between paragraphs
for linebreak add 2 spaces at end
_italic_ or **bold**
indent code by 4 spaces
backtick escapes `like _so_`
quote by placing > at start of line
to make links (use https whenever possible)
<https://example.com>
[example](https://example.com)
<a href="https://example.com">example</a>

formatting help »
answering help »