File System and Registry

Reviewed & published by Brayan K

By the end of this lesson you'll be able to list, create, copy, move, rename, read, write, and safely delete files and folders from PowerShell — the everyday skills that make the shell faster than clicking around in File Explorer.

Part of the free PowerShell course at LearnCodingFast — hands-on lessons with worked examples and the output they print, plus practice exercises and a quick quiz.

What You'll Learn

• List folder contents with Get-ChildItem (gci / ls) and move around with Set-Location (cd)
• Create files and folders with New-Item using -ItemType
• Copy, move, and rename with Copy-Item and Move-Item
• Read and write file content with Get-Content, Set-Content, and Add-Content
• Check a path safely with Test-Path before you act on it
• Delete safely: preview with -WhatIf before using Remove-Item -Recurse

💡 Real-World Analogy

Think of PowerShell as a universal remote control for storage. A normal remote only works with one TV; PowerShell's remote works with any device that speaks the same protocol. That protocol is the provider model: the file system, the Windows Registry, environment variables and certificates are all exposed as lettered "drives" (C:, HKCU:, Env:, Cert:). Because they all share one interface, the same verbs — Get-ChildItem, Set-Location, New-Item, Remove-Item — drive every one of them. Learn the buttons once and they work everywhere.

1. The Provider Model

A provider is an adapter that makes some data store look like a disk drive, so you can browse it with file-style commands. Get-PSProvider lists the adapters; Get-PSDrive lists the drives they expose. The big payoff: once you learn the file-system cmdlets below, the exact same commands also work on the registry and environment variables — you just point them at a different drive.

# A "provider" exposes some data store as if it were a disk drive.
# Get-PSProvider lists them; Get-PSDrive lists the drives they expose.
Get-PSProvider | Select-Object Name, Drives

# Because the FileSystem and Registry are BOTH providers, the SAME
# commands work on each — you just point them at a different drive.
Set-Location C:\           # move into the C: file-system drive
Set-Location HKCU:\        # move into the registry "current user" drive (Windows)

2. Listing & Navigating

Get-ChildItem shows what's inside a folder — its aliases gci, ls and dir all run the same cmdlet, so use whichever feels natural. Set-Location (alias cd) moves you into a folder, and Get-Location (alias pwd) tells you where you are. Add -Recurse to dig into every sub-folder and -Filter to match a name pattern.

# Get-ChildItem lists what's inside a folder. Aliases: gci, ls, dir.
Get-ChildItem -Path C:\Projects

# Set-Location changes the current folder. Aliases: cd, sl.
Set-Location C:\Projects\my-app
Get-Location                       # where am I now?  (alias: pwd)

# -Recurse digs into sub-folders; -Filter narrows by name pattern.
Get-ChildItem -Path C:\Projects -Recurse -Filter "*.log"

3. Create, Copy, Move & Check

New-Item makes both files and folders — the -ItemType switch decides which. Copy-Item duplicates a file; Move-Item relocates it, and when the destination is just a new name in the same folder it acts as a rename (so you rarely need Rename-Item). Test-Path returns a plain True or False, which makes it perfect for an if check before you create or delete anything.

# New-Item makes files OR folders — choose with -ItemType.
New-Item -ItemType Directory -Path ".\reports"            # a new folder
New-Item -ItemType File -Path ".\reports\june.txt"       # an empty file

# Copy-Item duplicates; Move-Item moves OR renames (no separate Rename needed).
Copy-Item ".\reports\june.txt" ".\reports\june-backup.txt"
Move-Item ".\reports\june.txt" ".\reports\2026-june.txt"   # this is a rename

# Test-Path returns a plain True/False — perfect for an "if".
Test-Path ".\reports\2026-june.txt"

Now you try. The script below is almost complete — fill in the three blanks marked ___ using the hints in the comments, then run it and check your output against the expected lines.

# 🎯 YOUR TURN — replace each ___ then run it in PowerShell.

# 1) Create a folder called "notes" in the current directory
New-Item -ItemType ___ -Path ".\notes"          # 👉 Directory or File?

# 2) Write a first line into notes\todo.txt (this also CREATES the file)
Set-Content -Path ".\notes\todo.txt" -Value ___    # 👉 some "text in quotes"

# 3) Append a second line to the same file
___ -Path ".\notes\todo.txt" -Value "Walk the dog"  # 👉 which cmdlet APPENDS?

# Already wired up — reads the file back once your lines work:
Get-Content ".\notes\todo.txt"

# ✅ Expected output (if line 2 was "Buy milk"):
#    Buy milk
#    Walk the dog

4. Reading & Writing File Content

Three cmdlets cover almost everything: Set-Content writes the file (replacing whatever was there), Add-Content appends a new line to the end, and Get-Content reads it back. One thing surprises everyone: Get-Content returns an array of lines, not a single block of text — so (Get-Content file).Count is the line count and [0] is the first line.

# Set-Content WRITES (and overwrites) the whole file.
Set-Content -Path ".\reports\log.txt" -Value "Service started"

# Add-Content APPENDS a new line to the end.
Add-Content -Path ".\reports\log.txt" -Value "Request handled"
Add-Content -Path ".\reports\log.txt" -Value "Service stopped"

# Get-Content READS the file. It returns an ARRAY: one item per line.
Get-Content -Path ".\reports\log.txt"

# So .Count is the number of lines, and [0] is the first line.
(Get-Content ".\reports\log.txt").Count     # 3
(Get-Content ".\reports\log.txt")[0]        # the first line

5. Deleting — Safely

Remove-Item deletes files and folders. To remove a folder and its contents you must add -Recurse — and that is exactly where accidents happen, because there is no recycle bin to undo it. The safety habit: run the command first with -WhatIf, which prints every action it would take without changing a single byte on disk. When the preview looks right, run it again without -WhatIf.

# Remove-Item deletes. On a FOLDER you must add -Recurse to remove
# its contents too, otherwise PowerShell prompts you for confirmation.

# ALWAYS preview first with -WhatIf — it shows what WOULD happen,
# but changes nothing on disk.
Remove-Item ".\reports" -Recurse -WhatIf

# Happy with the preview? Run the real thing (drop -WhatIf).
Remove-Item ".\reports" -Recurse

Your turn again. Guard the delete with Test-Path so it only runs when the folder exists, and preview it safely. Fill in the two blanks:

# 🎯 YOUR TURN — only delete the folder if it actually exists.

$folder = ".\notes"

# 1) Check whether the folder exists (returns True / False)
if (___ $folder) {                  # 👉 which cmdlet checks a path exists?

    # 2) Preview the delete safely first — add the right switch
    Remove-Item $folder -Recurse ___    # 👉 the "preview, change nothing" switch

    Write-Output "Previewed delete of $folder"
} else {
    Write-Output "Nothing to delete"
}

# ✅ Expected output (when .\notes exists):
#    What if: Performing the operation "Remove Directory" on target "...\notes".
#    Previewed delete of .\notes

Common Errors (and the fix)

• Deleting a whole tree by accident: Remove-Item .\folder -Recurse wipes everything inside with no undo. Fix: run it once with -WhatIf first to preview, then remove the switch.
• "A positional parameter cannot be found": usually a path with spaces that isn't quoted, so PowerShell splits it. Fix: quote the path — Get-Content "C:\My Reports\june.txt".
• Treating Get-Content as one string: it returns an array of lines, so string operations behave oddly. Fix: use [0] for the first line, .Count for the line count, or Get-Content -Raw for the whole file as one string.
• "Cannot remove item ... it is being used": the file is open in another program. Fix: close the program (or stop the process) holding the file, then retry.
• New-Item creates the wrong thing: leaving off -ItemType or mistyping it. Fix: be explicit — -ItemType File or -ItemType Directory.

Pro Tips

• 💡 Preview destructive commands with -WhatIf; PowerShell supports it on Remove-Item, Move-Item, Copy-Item and more.
• 💡 Quote every path. It costs nothing and saves you the day a folder has a space in its name.
• 💡 Live-tail a log with Get-Content app.log -Wait — it's PowerShell's tail -f.
• 💡 Pipe into Select-String to grep through files: Get-ChildItem -Recurse -Filter *.ps1 | Select-String "TODO".

📋 Quick Reference

Mini-Challenge: a Daily Log Tool

No blanks this time — just a brief and an outline to keep you on track. Build it, run it, and check the result against the comment. This is exactly the kind of small script that automates a real chore.

# 🎯 MINI-CHALLENGE: a tiny "daily log" tool
# 1. Make a folder ".\daily" (use New-Item -ItemType Directory).
# 2. Write today's date as the first line of ".\daily\entries.txt"
#    (use Set-Content with  (Get-Date).ToString("yyyy-MM-dd") ).
# 3. Append two log lines with Add-Content.
# 4. Print how many lines the file now has
#    (hint: wrap Get-Content in parentheses, then .Count).
# 5. SAFETY: preview deleting the folder with  Remove-Item ... -Recurse -WhatIf
#
# ✅ Expected (after 3 lines written): the number  3

# your code here

🎉 Lesson Complete!

• ✅ One set of cmdlets works across every provider drive (C:, HKCU:, Env:)
• ✅ Get-ChildItem lists, Set-Location navigates, Get-Location tells you where you are
• ✅ New-Item -ItemType creates files or folders; Copy-Item/Move-Item duplicate, move and rename
• ✅ Set-Content writes, Add-Content appends, Get-Content reads (as an array of lines)
• ✅ Test-Path guards your actions; Remove-Item -Recurse deletes — always preview with -WhatIf first

Practice quiz

Continue this course

• Previous: Functions and Scripts
• Next: Automation and Task Scheduling — Schedule scripts with Task Scheduler, use WMI, and automate repetitive admin tasks

Frequently asked questions

What's the difference between New-Item -ItemType File and Directory?

Both use the same cmdlet; the -ItemType switch decides what gets created. -ItemType File makes an empty file at the path, and -ItemType Directory makes a folder. Forgetting -ItemType (or getting it wrong) is the most common New-Item mistake.

How do I rename a file in PowerShell?

Use Rename-Item for a pure rename in place, e.g. Rename-Item old.txt new.txt. Move-Item also renames when the destination is a new name in the same folder, so Move-Item old.txt new.txt does the same thing. Both work; Rename-Item reads more clearly.

Why does Get-Content give me an array instead of one string?

Get-Content reads a text file line by line and returns an array with one element per line. That means (Get-Content file).Count is the line count and [0] is the first line. If you genuinely need the whole file as a single string, use Get-Content -Raw.

Is Remove-Item -Recurse dangerous?

Yes — -Recurse deletes a folder and everything inside it, and there is no recycle bin for it. Always run the command once with -WhatIf first: it prints exactly what would be removed but changes nothing. Only when the preview looks right should you drop -WhatIf.

Do I really need quotes around paths?

You need quotes whenever a path contains spaces, e.g. "C:\My Reports\june.txt". Without quotes PowerShell treats the space as a separator and reads "C:\My" as the path. Quoting every path is a safe habit even when there are no spaces.