Restart has become very slow

Yes, Restarts are often a little slower. I would not worry (as long as cold-boots are fast).

There is a "Fast Startup" option. Sounds counter-intuitive, but you can just switch that OFF. Not only does it INCREASE Windows Shut-Down time (which still has to happen, even with a Restart) ...

it is just NOT NEEDED, because you should be booting from a very fast NVMe SSD.

Try to do a clean boot which can resolve the issue.

Below steps would help you clean boot:

Click Start, type msconfig in the Start Search box, and then press ENTER.

If you are prompted for an administrator password or for a confirmation, type the password, or provide confirmation.

Configure Selective Startup options:

1. In the System Configuration Utility dialog box, click Selective Startup on the General tab.
2. Click to clear the Load Startup Items check box.
   1. Note The Use Original Boot.ini check box is unavailable.
3. Click the Services tab.
4. Click to select the Hide All Microsoft Services check box.
5. Click Disable All, and then click OK.
6. When you are prompted, click Restart.

Run SFC scan Now:

1. Open an elevated command prompt. To do this, click Start, click All Programs, click Accessories, right-click Command Prompt, and then click Run as administrator. If you are  

prompted for an administrator password or for a confirmation, type the password, or click Allow.

2. At the command prompt, type the following command, and then press ENTER: sfc /scannow

The sfc /scannow command scans all protected system files and replaces incorrect versions with correct Microsoft versions.

Also, check if the issue persists in safe mode with networking. Restart the computer and tap F8 on Dell logo and select Safe mode with networking. Now try to shutdown the computer and check if it takes same time to shut down.

Thanks for the reply. If it was a little slower, I would live with it. As it was the case previously.

But now it takes nearly 3 mins or more for the restart. SHut down and Fresh start is still quick. Hopefully it will stay as is.

Not sure what has caused this change for the last few days.

Thanks for the reply. I have followed all the steps mentioned in your post.

Unfortunately, nothing worked. Additionally I did the following:

Reinstall the display driver.

Adjusting the paging file size....

restore health etc.

I am worried nothing is helping.

The shutdown and fresh start is very quick.

It is only when I do a restart, the shutdown is quick, when it starts on the dell logo the dots keep rotating for 3 minutes and then the login screen comes.

I wish I could get any help ?

Yes, I remember them, it's the audio and wifi drivers.

After I reinstalled the audio driver (Realtek Audio Driver) it restarted working normally. You can try it (https://www.dell.com/support/home/en-us/product-support/product/xps-15-9500-laptop/drivers)

I had the same problem after installing a new driver, I think the root cause is from the new driver so I hope the support team can investigate and help us fix the problem

Thanks

Do you remember which driver, we can try uninstalling it ....

I'm having the exact same problem for around a week. Going to try to reinstall drivers as mentioned by Phi Nguyen.

Thanks, @bouchepat 

This works well. Appreciate your help.

Let's hope Dell can work on this. As we know, Windows 11 is also around the corner.

These buggy drivers may create lots of problems for users.

Thanks for pointing out the real problem.

For me, reinstalling the same driver did not work.

The solution suggested by @bouchepat  works well

I can't believe it was that simple...

I honestly thought something was completely wrong with my XPS 15 9500 and I had to host a class in the next 10 mins, so I kept force shutting it down. I ended up restoring the system to a previous version, which messed up my entire BitLocker encryption. 

I clean reinstalled Windows 10 and updated the drivers, but this issue was still there. I feel so disappointed at Dell and Realtek for having a single audio driver cause this and never be addressed. 

Yes, yes, yes, I looked everywhere for a solution -this works. 

Thank you for this info!

+2 decades of working on Dell PCs and I just now creating an account so I could give this a thumbs up.  I've never had a solution work so well and so simply,  Cheers to you @bouchepat