Hi Dexture.
Thanks for your post in Microsoft Community.
In your description, you accidentally deleted an environment variable (you didn't remember to change it) and now every time you start it, you get "C:\Program Files\WindowsApps\Microsoft Windows.Cross Device_1.24041.35.0_x... \Cross DeviceService.exe
The system cannot find the environment option entered." The prompt.
Please enter safe mode by the method in the link below, in safe mode, check your environment variables and other contents including windir, PSModulePath, TEMP, etc. and save them, then enter the system again in normal mode to check if the environment variables are the same as the configuration items mentioned above. If they are different, use the environment variable paths in safe mode.
If your environment variable path in Safe Mode is the same as in Normal Mode, or if this prompt still exists after you start your computer after making the changes, then if you have set up a restore point, please go through the following steps to try to perform a restore at the restore point you had before you changed the environment variables.
1 Press the Windows logo key + I on your keyboard to open Settings. If this does not work, select the Start button and then Settings.
2 Select Update & Security > Recovery.
3 Under Advanced Startup, select Restart Now.
4 After the computer reboots to the "Select Options" screen, select "Troubleshooting" > "Advanced Options" > "System Restore". Then restore through the corresponding restore point.
If you are not able to restore via a restore point, please try to repair the system by overriding the installation using the steps in the following link.
Disclaimer: At this point, we have exhausted all troubleshooting and I recommend that we try to perform a clean install to get your computer back into a Please ensure that you backup any important data, including Documents, Pictures, Videos, and more. After that, you can find instructions on how to install Windows 10/11 in the following article by MVP Andre: How to: Perform a Custom Installation of Windows 11 and Windows 10 or - Microsoft Community
When you change the environment variable again, to avoid errors that are difficult to fix, we recommend that you copy and paste it outside to make a backup before editing it.
I hope the above helps, if you have any other questions please continue to contact me, thank you for your support and understanding.
Best regards,
Zev - MSFT | Microsoft Community Support Specialist