Windows for Beginners

The Command Prompt (cmd.exe) is the classic shell that passes plain text between commands. PowerShell is the modern shell whose pipeline passes objects with real properties, so you can filter and sort by property instead of scraping text. Both ship with Windows and open in similar-looking windows, but they are different tools with different command styles.

Because your window is running as a standard user, and you tried to change a protected system area such as C:\Windows. The NT kernel enforces permissions regardless of who owns the machine. It is the security model working, not a fault. You can elevate to administrator rights when a task genuinely needs it, but doing so sparingly keeps you safer.

A path starts with a drive letter such as C:, then folders separated by backslashes, ending in the file: C:\Users\You\Documents\budget.xlsx. Windows uses backslashes, unlike Linux and the web which use forward slashes. The Command Prompt expects backslashes, while PowerShell accepts either.

Usually not. Most commands and daily tasks work fine as a standard user, which is the safe default. Only elevate to administrator when a task truly requires it, such as installing system software. Staying a standard user limits the damage a bad download can do, because it cannot reach protected system areas.

Five layers: the NT kernel that enforces permissions and talks to hardware; the registry, a central settings database; services, which are background programs without windows; user accounts and their rights; and the shells and apps where you type or click. Picturing these layers makes the rest of Windows much easier to understand.

CMD checked its built-in commands, then searched the current folder and every folder in the PATH variable, trying extensions such as .EXE and .BAT, and found no match. Usually it is a typo. Otherwise the program is installed but its folder is not in PATH; run where with the name, or call the program by its full path in quotes.