Installed Windows 7 Ultimate (64-bit) on a fresh PC and after installing service pack 1 started the upgrade to Windows 10. The assistant app downloads and verifies but gets stuck at 99% in the upgrading window phase. Even after hours it remains stuck there.

I've tried to reboot the machine and that doesn't help either. I've googled and found out that others have faced the exact problem but so far there isn't any solution that works.

Has anyone seen that situation and is there a fix for it?

  • 4
    whats with the downvotes?
    – Shoaib
    Commented Jun 3, 2016 at 6:03
  • - Your question has recieved zero downvotes....
    – Ramhound
    Commented Jul 1, 2016 at 21:38

7 Answers 7


The problem is caused by the Windows 7 updates.

Before using the Windows 10 Upgrade Assistant, perform these steps:

  • set Windows 7 updates to "Never install updates".
  • Stop the update service by right clicking on the command prompt, and choose "Run as administrator".
  • Type


    It should say: "Windows update service is stopping....windows update service is stopped." Windows update service is stopping

After completing the above steps, start the Windows 10 Upgrade assistant, and it should complete.

  • Your Welcome eFriend Commented Jun 23, 2016 at 14:52
  • I had to make sure all the important windows updates in Win7 have been installed (which took some effort, since some of them been failing and had to solve that). Then proceeded with disabling automatic updates and the update service and finally succeeded with upgrade. Thanks!
    – Mchl
    Commented Jun 30, 2016 at 15:48
  • Worked for me!! It was stuck at 99% for 8+ hours, followed these steps and now it just went to 100% and rebooted! Thanks! Commented Sep 26, 2016 at 15:48
  • 100% was reached, but then Upgrade App started downloading Win10 second time, 100% was reached again, then it switched to interface similar to Media Creation Tool and finally it worked. Thanks. Commented Dec 16, 2016 at 8:34
  • Worked for me too. Another documented Microsoft issue that will stand for years!
    – luison
    Commented Apr 25, 2017 at 8:45

Here is what I've learnt about upgrading to Windows 10, in the past few days.

Media Creation Tool

The good thing is that the upgrade completes smoothly once the download has completed.

The bad thing is that it doesn't resume interrupted downloads. The download is over 3GB which is almost 3x the amount downloaded by UpgradeAssistant.

Common Problems
Once interrupted (esp. crashed or rebooted) you won't be able to launch the tool again without manually deleting the $Windows.BT and $Windows.~WS folders first. However, in order to delete these folders you'll need to use Process Explorer (from sysinternals) and forcefully close all open handles to files in these folders. Search for "$Windows." and close every handle that you find.

In my case, after each interruption (I had four) it would add 3.02GB to the download - basically start downloading +1 BITSXYZ.tmp files. With 5 downloads of over 15GB I had to say goodbye to this method as nothing I did could reset the tool to its initial state.

Don't use this method unless you have a reliable power-source and good internet.

Upgrade Assistant App

Very good at resuming broken downloads and it downloads only what is needed for your system therefore a much faster method. The downside is that the upgrade isn't a smooth process.

Common Problems
Upgrade will get stuck at 99% and there doesn't seem to be a single solution that works for everyone. First, its better to resolve missing driver issues before upgrading (as suggested by other answers). Here is what I did to get past 99%.

  1. Let it run for sufficiently long time say 3 hours.
  2. Set startup type for the windows service: "Windows Update" to "manual" for the duration of the upgrade, this will prevent it restarting itself when you perform the next step.
  3. Stop the windows service: "Windows Update" and wait a couple of minutes
  4. If this doesn't help start the service again.
  5. Use process-explorer to kill SetupHost.exe that is a child of WindowsUpgradeAssistantApp.exe.
  6. Wait for the assistant to report "Something went wrong," and use the "Try Again" option. This should repeat the usual download, verify and install cycle except that at about 45% a blue interface will popup.

The new popup UI will start in "Getting Updates," phase and believe it or not there are far more reported incidents of that getting stuck. To resolve it:

  1. Stop "Windows Update" service
  2. Clear all contents of "C:\Windows\SoftwareDistribution"
  3. Start the service again (if needed).

This should hopefully unblock the tool, but it will come back to the "Getting Updates" state again. Give it some time and if it gets stuck again, follow Step 1 and 3-4.

Once past this point the "real upgrade" would begin and hopefully that would be a smooth process.

  • 1
    Bless you. In the Upgrade Assistant App, once it starts getting close to 90%, mid 80s, it starts to slow down a lot for me. Up to that point might be a total of 30-40 minutes. By 96% it can start taking up to an hour between increments till it gets to 99% (where it freezes). These steps worked perfectly. Commented Jul 20, 2016 at 9:10
  • 3
    Great, this fixed my issue with Win 10 Upgrade Assistant. I would be interested, why Microsoft doesn't disable the Windows Update service itself during Win 10 Upgrade ^^
    – Simon
    Commented Aug 1, 2016 at 7:57
  1. Click Never check update in Control Panel.
  2. Power off the computer.
  3. Run the Windows 10 download installer again.
  • 2
    I wouldn't recommend step 2 and 3 unless you want to start back over from 0%. Step 2 is just performing the stopping of Windows Update after it's been disabled, better to just follow the command prompt route to disable wuauserv than it is to reboot entirely. Commented Sep 26, 2016 at 15:51

Same problem. Very simple solution worked for me: opened Services and stopped and disabled Windows Update service.


I had the same problem with my old Lenovo T500 I tried 3 times and it stopped at 99 percent then I checked my system, and I found out in the device manager that not all the drivers been installed properly I went to download all the drivers and tried again then it worked fine.. it passed the 99 % and 45 minutes later my Windows 10 was installt without problems

I hope that works for you as well

  • Does not work. Win10 upgrade is most definitely MS's shame of the century; a show-stopper. Upgrade-Assistant doesn't go past 99% and MediaCreationTool adds 3.02GB download each time its interrupted. If I start it would download 5 BITSXYZ.tmp files each 3+GB.
    – Shoaib
    Commented Jun 8, 2016 at 12:08
  • make sure no external disks are connected and that you have enough space on your primary disk
    – yarg
    Commented Jul 12, 2016 at 8:19

I had three machines that did the exact same thing. I found the problem to be a drive imaging program that I had installed on all three machines. After giving up after about 12 hours i reboot the machines to find that they would only give me a mouse cursor and background screen. To fix the problem I boot all three into safe mode , did a system restore going back before i had installed the drive imaging program ( 1 week) . After the system restore i ran the win10 upgrade and it went right through on all three machines with no problems.


I was successful with

  • waiting more than 24 hours (old machine, was at 99% after 1-2 h, then stayed at 99% for 24-33 h). during this time cpu usage was around 25% and memory was not at the limit.
  • after 24 h I de-installed some tools that I was suspecting to interfere with the update process (avira antivirus and tune-up and some norton tool), so this could have been the reason, too.
  • I waited 2 days at 99% with internet and virus checker off after the download. Suddenly it rebooted into Windows 10 and continued the upgrade. Finished after a few reboots in 2 hours. It is a three year old laptop, i5 but slow.
    – vinnief
    Commented Dec 3, 2016 at 19:58

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