CompTIA A+ Operating Systems Summary

ipconfig lists the network settings of each adapter, including IP address, subnet mask, and default gateway. ipconfig /all adds more detail, such as DNS servers and the MAC address.

Wrong choices

• nslookup: nslookup asks a DNS server about a name. It does not show the PC's IP settings.
• tracert: tracert shows the path to a remote host, not the PC's own IP settings.
• ping: ping tests whether another device can be reached. It does not list the PC's own settings.

Event Viewer keeps logs of what happens in Windows, such as application errors, system warnings, and security events like sign-ins. It is a good place to look when you need to know what went wrong and when.

Wrong choices

• Disk Management: Disk Management manages drives and partitions, not logs.
• Task Scheduler: Task Scheduler runs tasks at set times. It does not show the system's error logs.
• Device Manager: Device Manager lists hardware and drivers. It does not keep the system's event logs.

FAT32 is an older file system that works with almost any device, but one file on it cannot be bigger than 4 GB. Reformatting the drive as exFAT or NTFS removes that limit. Formatting erases the drive, so copy off any files first.

Wrong choices

• The flash drive is full: The drive has 32 GB free, which is plenty of space for a 6 GB file.
• Video files must be compressed before copying: Video files do not need to be compressed to copy. The file size limit is the issue.
• Only administrators can copy video files: Copying a video file to a flash drive does not require administrator rights.

System File Checker (sfc) checks Windows system files. Running sfc /scannow from an administrator command prompt finds damaged or missing files and replaces them with good copies.

Wrong choices

• gpupdate: gpupdate applies Group Policy settings. It does not repair files.
• ipconfig /renew: ipconfig /renew asks DHCP for a new IP address. It has nothing to do with system files.
• chkdsk: chkdsk checks a disk's file system and surface for errors. It does not replace Windows system files.

Windows Home editions cannot join a company domain. Pro and higher editions can, and they also add business features such as BitLocker and Group Policy Editor. The fix is to upgrade the edition.

Wrong choices

• Create a new local administrator account: A new local account does not give Windows Home the ability to join a domain.
• Install Group Policy Editor from the internet: Domain join is a feature of the edition. Downloading a tool does not add it.
• Turn on BitLocker: BitLocker encrypts the drive. It does not add the ability to join a domain, and Home does not include it.

In Linux and macOS terminals, ls lists the files and folders in a directory. Common options include ls -l for details and ls -a to show hidden files.

Wrong choices

• cd: cd changes to a different directory. It does not list files.
• pwd: pwd shows the full path of the current directory, not its contents.
• chmod: chmod changes file permissions. It does not list files.

Time Machine is the macOS backup tool. It copies files to an external drive or network location and keeps hourly, daily, and weekly versions so you can restore older copies.

Wrong choices

• Keychain: Keychain stores passwords and certificates, not file backups.
• Spotlight: Spotlight searches for files and apps. It does not back them up.
• FileVault: FileVault encrypts the Mac's drive. It does not make backups.

Task Manager has a Startup tab (Startup apps in Windows 11) that lists programs that launch at sign-in. Disabling the ones the user does not need makes startup faster.

Wrong choices

• Device Manager: Device Manager controls hardware and drivers, not startup programs.
• Event Viewer: Event Viewer shows logs. It does not turn startup programs on or off.
• Disk Management: Disk Management manages drives and partitions, not startup programs.

Installing software changes system files, so it needs root (administrator) rights. Putting sudo in front of the command, such as sudo apt install, runs that one command with those rights after the user enters their password.

Wrong choices

• Use chmod to give everyone full permissions on all files: Opening up permissions on every file is a serious security risk and is not how software installs are allowed.
• Restart the computer and try again: A restart does not give the user administrator rights.
• Run ls to list the files in the folder: ls only lists files. It does not give the rights needed to install software.

Windows applies Group Policy changes on a schedule. gpupdate /force tells the PC to apply all policy settings right now. To see which policies are in effect, use gpresult.

Wrong choices

• sfc /scannow: sfc repairs system files. It does not apply Group Policy.
• chkdsk /f: chkdsk fixes file system errors on a disk. It does not apply Group Policy.
• gpresult /r: gpresult shows which policies are applied. It does not apply new ones.