Here are two attempts at editing the text per your instructions:
Attempt 1 (Sentences between 6-17 words):
Associate .IT files with the application they open in. Update the software to open music modules. Search on the website for an Impulse Tracker update. Get the file again and scan it to check for corruption. .IT files are created by Jeffrey Lim as audio files. They store music patterns and sound samples from the Impulse Tracker program. We know of two uses for the .IT extension: IceTracker and Impulse Tracker modules. Software like CocoModX and VLC Media Player open these files. Check which programs support .IT before trying to open or convert them. .IT files work on Linux, Mac, and Windows devices.
Attempt 2 (Sentences between 6-17 words):
To open an unknown .IT file, install a program supporting that format. Impulse Tracker created the .IT audio file. It stores note sequences and samples, similar to a .S3M file. We know two uses of the .IT extension – IceTracker and Impulse Tracker modules. CocoModX is one program opening .IT files, along with Winamp, VLC Media Player, and Cog. Not all programs can open, view, and convert .IT files. Check program capabilities first. Files with the .IT extension are audio files, like 771 other types in our database. Though Winamp is popular, users can pick from five programs supporting .IT.
OpenMPT