assistant: I understand you are unable to shutdown your computer and will try to provide options to resolve this issue without the need to reboot. Here are a few suggestions: 

1.) Since you mentioned "the window has become larger than everything else" this may be caused by the full screen mode option in your browser. Press "F11" key on your keyboard to disable this mode. If this does not solve your issue you can press F11 again to disable this mode.

2.) If this does not work you can attempt manually end the browser process via task manager. Try pressing the "Ctrl + Alt + Delete" keys on your keyboard. This should bring up the Task Manager. If you can see the Task Manager, try ending any non-essential processes such as Chrome, Firefox or Edge to free up resources. 

3.) Another options is to wait until the files on the USB stick have finished transferring over to your computer. If you are unable to determine the progress of the file transfer it would be best to wait overnight to allow the transfer to complete before attempting to rebooting your computer. If you are still unsure if the transfer is complete after this, you may need to seek additional assistance from a relative or technician.

I hope these steps help you resolve the issue and get back to using your computer normally. Let me know if there's anything else I can assist you with.

assistant: Don't worry, I'll help you find out what happened and get your computer back into normal working order! 
Your grandson is right that removing a USB stick or shutting of your computer while files are transferring. Doing so has a small chance of causing those files or the USB stick to become corrupted and unreadable!
If you can, you should also avoid turning off your computer using the power button, since this can cause unnecessary wear and tear to your computer's electrical components and reduce its operating life. If you have the option, you should shut it down with your operating system to minimize component wear and avoid the possibility of damaging your files.

From your description, it sounds like you encountered an operating system error that caused it to crash. It may look frightening, but operating systems can sometimes detect a crash and fix it without you needing to turn of your computer. You should be safe this time to shut if off, but I would recommend waiting a few minutes to see if the computer ends up fixing itself first. 

In the meantime, could you tell me a bit more about this problem? Is this the first time this has happened, or have you encountered it before? If so, is it a regular problem? 

I'll also need know what type of computer you have and it's specifications to give you the best support I can.

prompter: My computer is the one from Aldi. And it's not the first time it's done this! Usually I'll hold down the button and start it again but I'm not sure if my pictures have done copying yet. I went to Spain with my grandson for a weekend and it was just so great. We have some really pretty pictures of him and me together and I don't want to lose them. I have so few photos of him as is and he usually doesn't have the time to go on a holiday with his grandmother, but I mean who does anymore right?