I have two identical PCs running 8.1. They're almost clones. One, though, I use a lot more and it has a lot more files on it. So about a month ago when I started getting these delays, sometimes long ones, where the screen pales out, and nothing happens and at the top of the screen it will say something like Mozilla (Not Responding) or Paint (Not Responding) I thought maybe it was that pc. I mean, it's not my connection because it happens with both online and not online apps.

So I'm on this other one now, and it's nearly as bad. The only thing synced between the two is Firefox (oh, and Dropbox), but like I said, this is happening even when that's not in use. There's a lot more room on this one, over 100 gigs more, and just less stuff by way of files, apps, etc. on this one. But the same problem.

Anybody got a clue? Thanks very much!

Hi,

Based on your description, it's most probably caused by third-party software.

I suggest you perform a Clean Boot to disable all third-party software and services startup items to check the result:

How to perform a clean boot in Windows

https://support.microsoft.com/en-us/kb/929135

Meanwhile, run sfc /scannow command to check and fix the system file:

Use the System File Checker tool to repair missing or corrupted system files

https://support.microsoft.com/en-us/kb/929833?wa=wsignin1

Thank you Karen. That sounds like a lot of work for a problem that does not seem logical to me. Here's why:

1. Two identical computers, A & B.

2. A is in common usage and B is only for backup.

3. A has been in exclusive use since about May 1. B has not been turned on in all that time.

4. About June 1, A develops a problem.

5. Around July 1, I turn on B for the first time in months. Naturally, it automatically does a lot of updating, primarily Windows. When it finally lets me use it, it has the same new problem.

Ah. I perhaps see what you are saying. Maybe one of the other apps that updated introduced the problem. The only apps I have that updated are very common: Firefox, itunes, Malwarebytes, Flash player, Quicktime, etc. Have you heard of any problems with any of these?

Thank you,

Lily

Hi Lily,

The same program on different computer environment is different.

I still would like to suggest you perform the troubleshoot steps I provided above to check the result.

Thank you again -- I got a new keyboard which seemed to help, but now I have another problem I'll put in a new topic. Thanks, again.

Thank you again -- I got a new keyboard which seemed to help, but now I have another problem I'll put in a new topic. Thanks, again.

• Marked as answer by Karen HuMicrosoft contingent staff, Moderator 19 hours 10 minutes ago