main.go:3:8: package test/test is not in GOROOT (F:\go\src\test\test)

This error message indicates that Go is unable to find the package "test/test" in the GOROOT directory. The GOROOT directory is the location where Go is installed on the system.

To resolve this error, you can try the following steps:

1. Make sure that the package is located in the correct directory. In this case, the package should be located in F:\go\src\test\test.

2. Check that the package name is correct and matches the directory name. The package name should always match the directory name in which it is located.

3. Ensure that the GOPATH environment variable is set correctly. GOPATH is the location where Go looks for packages that are not part of the standard library. You can set the GOPATH environment variable to the directory where the package is located.

4. If the package is not part of the standard library, ensure that it is installed correctly. You can use the "go get" command to install the package.

5. If all else fails, try reinstalling Go on the system. This will ensure that all the necessary files and directories are present in the correct locations.