if you are in workgroup environment sometimes you might want to access shared folders and files, most people enable guest account to access shared folders in workgroup environment, but even you enable guest account in windows 10 you might run into error as following picture when accessing shared folders and files.
in order to solve this problems we have to enable insecure guest logons in group policy editor, to do that follow below steps.
1. press Win + R to open run
2. type gpedit.msc
3. navigate to Computer Configuration
4. Administrative Templates
5. Network
6. Lanman Workstation
7. now in the right side find and double click to open Enable insecure guest logons
8. select Enable and click apply and ok.
now restart pc to update group policy or we have to run command to update group policy immediately. to do that
1. open command prompt as administrator (hit window key > type cmd > right click cmd and run as administrator
2. type gpupdate /force and press enter
3. wait until computer policy and user policy to update
Now you should be able access shared folders and files without any problem.