Comment 1 by jteh on 2014-10-04 21:51
Are you absolutely certain this occurs on any OS? I've only ever seen (and heard of) this occurring on Windows 7 and it's due to a bug in Windows 7 (specifically, Explorer's UIA implementation).

Comment 3 by kayatli (in reply to comment 2) on 2014-10-05 02:16
Replying to jteh:
Yes. This occurs on all OS's. Win XP, Win 7, and Windows 8.1.

Comment 4 by jteh on 2014-10-05 02:35
Since you're the only user who's ever reported this outside of Windows 7, we need to question configuration, etc. on the systems that aren't Windows 7. What makes you certain that this is NVDA; i.e. can you confirm that Explorer doesn't slow down when NVDA isn't running? Are you using any NVDA add-ons?

Comment 5 by nvdakor on 2014-10-05 02:52
Hi,
A few more questions:

• Does this occur with other screen readers?
• Have you figured out a pattern (say, too many files and folders) that may cause this issue?
  Thanks.

Comment 6 by briang1 on 2014-10-05 09:00
The only ways I can induce this sort of behaviour in xp are purely windows related, ie not nvda related.
Having folders remain open as you go, rather than getting windows reused for the new one, with lots of the fluff enabled like shadows and animations on is one way to do this.
another way is to have an anti virus that seems to want to check every selected item in an opened foleder as you go down the list.

Might be worth looking at resource usage on his machien and see what is going on there.

Comment 8 by kayatli (in reply to comment 7) on 2014-10-05 19:13
Hi:
I've left my system on for a while running another screen reader and the slow population of lists and the lag doesn't occur. Also, I've noticed that even though restarting NVDA doesn't fix the issue completely, it does get rid of the slow list population issue and the lag when arrow up and down seems to be slightly less.

I've noticed that this occurs regardless of how large the list is.

Replying to blindbhavya:

Comment 9 by jteh (in reply to comment 8) on 2014-10-05 22:58
Replying to kayatli:

I've left my system on for a while running another screen reader and the slow population of lists and the lag doesn't occur.

To clarify, have you done this exact same test on Windows XP and Windows 8.1? This is the unknown part of the situation.

Comment 10 by kayatli on 2014-10-06 21:32
Yup. I've done the same test with 8.1 and XP.

Comment 11 by tonguyenchau1986 on 2015-08-24 06:33
I get the same problem. NVDA is slow down with windows explorer on windows 7, 8, 8.1 and 10. Notice that NVDA is only slow down with Windows explorer; and, normally speak with another windows.

Windows XP specific issues are no longer addressed and Windows 8 has been superceded by Windows 8.1. Thus, we need only focus on Windows 7 and Windows 8.1 for the purpose of this ticket. As a long-time Windows 8.1 user, I can confirm that I have been having no such issue since months with Windows Explorer. @jcsteh has acknowledged the presence of such a bug on Windows 7, attributing it to a problem on Microsoft's part. Have Windows updates on Windows 7 resolved this by any chance or does this issue still persist? In case it is the latter, is there anything that can be done from our end to address this in any way?

@kayatli are you still having this issue? @bhavyashah seems not able to reproduce it anymore. @Brian1Gaff Can you reproduce it still?

I have not seen this issue on Windows 8.1 and Windows 10 at all. And I am using the PC at work the whole day. I will close this issue since we have confirmations from Brian and @bhavyashah that the issue is not reproducible. If someone reports it, we can reopen it again.