Can't upgrade to Windows 10?

I have windows 7 and want to switch to 10 but every time I try I get an error message I have already tried to restart my laptop

Will probably not go in general. Just buy a key for a 10.

How do you mean?

The free upgrade was only for a short time.

Yes I know but the error message comes when I have to enter the key

The server will probably be switched off.

Did you use the media creation tool?

The update to Windows 10 from Windows 7 still works. I only did that yesterday!

Yes

Try it like this:

Use this tool to read out and note down the Windows 7 product key: https://www.downloads.focus.de/app/windows-8-product-key-viewer

Then use the Media Creation Tool to create a Windows 10 USB boot stick.
Boot the created stick and follow the instructions of the assistant. The installer offers the possibility to delete everything. You should do that.
If you are asked to enter the product key during installation, skip this step.
If Windows 10 is installed and it starts for the first time, it is recommended to create a Microsoft account if you don't already have one. Otherwise, log in to Windows 10 with your Microsoft account.
Then activate Windows 10 with the noted Windows 7 product key. The activation will then also be saved permanently in your Microsoft account.

If you have to reinstall Windows 10, just log back into Windows 10 with your Microsoft account. Then it is automatically reactivated. You no longer have to enter a product key.

I found that:

Modern setup host no longer works

(1), disable it. Disconnect any unnecessary external devices that are connected to the computer. Some report that low disk space can cause this problem… Restart your computer and restart the upgrade process