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IT Miro
IT Miro, Computer Scientist
Category: Software
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Experience:  Bachelor's Degree in Information Technology, Microsoft Certified Professional
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Error message. LogonUI.exe-System Error. Comctl32.dll is missing.

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Error message. LogonUI.exe-System Error. Comctl32.dll is missing. Cannot sign on computer at all black screen with error message

Hello! I am IT Miro and I will assist you on this question.

What Windows version are you using on that computer and when did the problem start to happen?

IT Miro
Customer: replied 4 years ago.
Windows8 and it happened earlier today. It is an Acer Aspire
OK. Do you have a Windows 8 installation or repair disk? You can use it to attempt to resolve this problem.

Customer: replied 4 years ago.
I will check
Customer: replied 4 years ago.
No I do not
Customer: replied 4 years ago.
Are u there ?
Yes, I am here. Sorry for the delay.

You should be able to access Automatic Repair or System Restore without Windows 8 disk.

Here is how to do that:

1. Restart your computer

2. While your computer is powering ON, press and hold down the Shift key and then keep pressing the F8 key

3. It will boot into Windows 8 Recovery so click on the See advanced repair options button. If it doesn't boot into Windows 8 Recovery, restart your computer and try again - press and hold down the Shift key and keep pressing the F8 key

4. On the Choose an option screen, click on Troubleshoot

5. On the Troubleshoot screen, click on Advanced options

6. Now you can choose from several useful options. First, I would suggest to use Automatic Repair which should repair all known startup problems

7. So, click on Automatic Repair and wait until it repairs found Windows 8 problems. Then, restart the computer and see if it helped

In case it didn't help, repeat the steps 1-5 and select System Restore instead of Automatic Repair. There select a date when you know your computer operated just fine. It will then restore Windows 8 settings to an earlier point in time, which should solve the problem you are having.

Let me know how it goes.

IT Miro
Customer: replied 4 years ago.
Ok I am thinking I may windows 7 as the screen did not come up as that but safe mode choices
No problem. The procedure for Windows 7 is similar.

First, restart your computer and then keep pressing F8 button rapidly and you should see Advanced Boot Options menu which looks like this:


Once you see that menu, select Repair Your Computer option and press Enter. Wait a while and follow the on-screen instructions. You should get to the window that has several repair options, including Startup Repair, as shown on this image:


So, click on Startup Repair which should fix all found startup problems.

Once it has finished, your computer should restart and operate normally.

However, if it is still the same, repeat the instructions to go back to System Recovery Options window, but now select System Restore:


When you click on System Restore, follow the on-screen instructions where you can choose one restore point based on a date to revert system settings back to that date (when all worked fine). Wait for the process to finish and it will automatically restart a computer. Hopefully, your problem will be gone. Don't worry about your personal files as they won't be affected by System Restore.

I hope this helps!

IT Miro
Customer: replied 4 years ago.
Ugh. Not seeing option for repair
Hmm. Do you have a Windows 7 disk?

What happens when you choose Safe Mode?

Customer: replied 4 years ago.
I think I got to the right place please hold
OK. Good luck. Smile

Customer: replied 4 years ago.
I did system restore. Should it be taking this long?
Up to 10 minutes is normal for System Restore.

Customer: replied 4 years ago.
It just says restoring files been over 20 minutes :(
Hmm. It shouldn't take so long. But, since it is not wise to interrupt the process, just wait as long as it is needed.

I am sure it will finish within several minutes.

Customer: replied 4 years ago.
Still saying same thing no change
That's bad. Check Safe Mode now to see if you can enter it.

Customer: replied 4 years ago.
No same error message as before
Let me check something to see what else I can recommend to you in this situation.

Customer: replied 4 years ago.
Customer: replied 4 years ago.
Are we done? Am I being charged?
Hi! I was away from the computer for a while.

No, we are not done, of course.

Do you remember installing any program recently?

Customer: replied 4 years ago.
No nothing that I can think of
OK. I am not sure which program or what change caused this error, but your computer is missing the comctl32.dll file. It's location is in C:\Windows\System32

That file is needed for Windows 7 start up. You can use Windows 7 installation disk to copy that file from the disk to your computer, or any other method which gives you Command Prompt and a backup of original comctl32.dll file.

So, do you have Windows 7 disk?

Customer: replied 4 years ago.
No. Can I buy one?
No need to buy one to solve this problem. Having a Windows 7 would only ease the solving of this problem since comctl32.dll file is already located there and you can have Command Prompt window shown easily.

Don't worry, there are several other solutions. I will explain one of them now.

I just want to know if you have another working computer where you can burn a blank CD? I will give you a download link for an ISO file which needs to be burned onto a blank CD which you will then be using to solve the problem for the computer in question.

Customer: replied 4 years ago.
Neighbor just brought one over
Oh, nice neighbor! Smile

I will provide the full instructions on how to proceed soon.

It seems there are different versions of comctl32.dll file, depending on if you have Windows 7 Service Pack 1 installed or not.

Do you know if you have installed Service Pack 1 for your Windows 7? In case you have Windows Update enabled, SP1 is most likely installed.

Customer: replied 4 years ago.
Neighbor just tried disk. No luck
Customer: replied 4 years ago.
No idea on what's installed.

OK, here is the first part of the instructions. Basically, you need to copy a working back up of comctl32.dll file to your computer.

1. Use another working computer to download a bootable BartPE CD. Here is the DOWNLOAD LINK

2. Next, download a working copy of comctl32.dll file on THIS LINK

3. You will also need an image burning program. I recommend Free ISO Burner which can be downloaded on THIS LINK

4. Install Free ISO Burner and wait until the bootable CD has been downloaded

5. Let me know what this is all downloaded/installed

Customer: replied 4 years ago.
Sure. Lol
Here is the second part of the instructions:

6. Start Free ISO Burner and click the Open button. Locate a bootable BartPE CD file you downloaded in step #1. Insert a blank CD and click the Burn button. Wait for several minutes until it finishes the burning process

7. Next, copy the comctl32.dll file you downloaded in step #2 to a removable USB flash or hard disk drive

8. When the CD has been burned, insert it into the computer that needs to be fixed and start it up (or restart if it is already started). You will need to boot from that CD. You can enable booting from CD drive by pressing the F10 or F12 key while the computer is starting up. It should display you a Boot selection window where you can select to boot from CD/DVD drive.

If that doesn't work, press F2 or Del/Delete key instead to enter BIOS where you can set CD/DVD drive as 1st boot device

9. Once you have booted from CD drive, wait until BartPE fully loads. You can now connect a removable flash or hard disk drive that contains the comctl32.dll file. You will notice that BartPE interface looks like Windows XP. Click No when it asks you whether to start network support or not

10. Start "Windows Explorer" by clicking Go > Programs > A43 File Management Utility. Expand the My Computer menu and locate your removable drive and right-click it and select Copy

11. Locate and expand your WindowsXXXXX(that contains a folder named Windows). Expand the Windows folder and expand the System32 folder. When you are there, right-click inside the System32 folder and select Paste. If asked whether to overwrite the file or not, click Yes

12. You have now put a working copy of comctl32.dll file so Windows 7 should work now. Exit BartPE environment by clicking Go > Shutdown > Restart. You can then eject the CD

13. Wait for Windows 7 to fully boot. It should work now with no errors.

However, if something doesn't work, let me know.

IT Miro
Customer: replied 4 years ago.
Sorry couldn't stay up any longer, will have a friend help me with this later. Will be in touch
Customer: replied 4 years ago.
Somehow my computer is up and running. Ran a system restore over night . It said that it did not restore but a few minutes later my sign on screen came up? Do u recommend that I still download the burned disc?
Good morning!

It's great that your computer is up and running again. You don't need to download and use the boot CD since you can now log on to your computer successfully.

However, please verify that the comctl32.dll file exists on your computer. It is located in:
Customer: replied 4 years ago.

Yes it is! crazy! thank you!

Great! I am sure Windows 7 will operate fine now, with no errors.

It seems System Restore successfully restored the comctl32.dll file, but failed on other files (which you already had on your computer so they weren't needed).

You can save my instructions for BartPE boot CD in case you cannot log on to your computer. It is usually used to fix some problems as well as to access your data.

Please take a moment to rate my service using one of the smiley faces near my answer. Feel free to ask any additional question you may have.

IT Miro
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