Hello, I have around 35000 text files (ASCII) from which I need to delete the lines 2, 3, 4 and 5. How could I do this with a PS script? Thank you very much!

Try this (make sure you test it on just one file first :) ):

$path = "file.txt"
$lines = Get-Content -Path $path
1..4 | ForEach-Object { $lines[$_] = $null }
Set-Content -Path $path -Value $lines

Try this on a test file:

$file = get-content test.txt
$file[0],$file[5..($file.length-1)] | out-file test.txt -encoding ascii

want another?

(gc file.txt) | ? {(2..5) -notcontains $_.ReadCount} | sc file.txt

Thanks! I used Shays code. Worked perfectly.