I wouldn't worry too much about it, as fresh Windows installs come with an empty path anyway.
Windows uses PATH to configure paths to directories that contain programs. It is used to make life easier and not have to type full paths to all exe files.
For example, if you download Tiny C Compiler, and unzip it in C:\, you would expect the path to to tcc.ece to be "C:\TCC\bin\tcc.exe".
If you open cmd up, and type tcc.exe, an error would return stating that path cannot be found. This is because Windows scans all its known paths for a match in the command you provided. By default, system32 folder is checked first, and PATH values afterwards.
If you add 'C:\TCC\bin' to PATH, windows will search in bin folder for matching names of commands you give. After applying thr new settings and re-opening the cmd prompt, you can enter 'tcc -h', and the conpiler will display an its help message to you.
In essence, it provides "windows-level" shortcuts to program locations. This can affect you if software you used relied on PATH. For example, if you had nmap installed, it will no longer be accessable via 'nmap' command via cmd.
Watch out for new error messages, which point to errors in paths, and steadily rebuild them.
Format of PATH is: C:\nmap\bin;C:\TCC\bin;C:Tools
Have fun