This depends on the file type in your subfolders, but the compression method you are using is not very high as well

>>In a compressed file it showed that it had compression "storing" and "srep:m3f:a1+lzma:69mb:normal:bt4:128:lc8".

"Storing" simply means "no compression"
Are you using MAsked data Compression or something
its probably that files compressed with "storing" are not compressible
at all thus decided to not use any compression at all
here are some of the thread helpful for you
read the post from other user, this is very helpful for all of us
http://fileforums.com/showthread.php?t=99120
http://fileforums.com/showthread.php?t=97530
http://fileforums.com/showthread.php?t=99122
http://fileforums.com/showthread.php?t=93191

How to fix it?

the sections look ok. so most probably you are using old arc.exe that doesn't understand them. other possibilities are that i don't see some problems, or there are invisible symbols (f.e. LF instead of CR+LF), or arc.ini read from other place

You are right. I am using freearc 0.40

Used fa 0.67. But when extracting using ISDone, the progressbar stuck at 0% and then immediately goes to 100%. I am using ISARCEXTRACT function and Cls-uharcmt.dll and cls-antiz.dll while compressing and decompressing. Anyone can help?

start with figuring out which method in chain do it, then ask the method author

The method is right, but I need to ask Razor12911 because he is the creator of those clses

What is the last version of srep that supports almos every version of windows? The latest srep 3.93a has a decompression bug in windows 10

Hey, I have a very simple question

can someone post a step-by-step tutorial on how to unzip ARC files in Inno Setup

Check Index and various scripts in the forum, no one is going to create a tutorial.

You can use either ISDone or ISFreeArcExtract script by shegorat

try -slp-

overall, i thinks that srep 3.9* is not fully debugged, so it's preferable to use 3.2 with -slp- switch

3.2 works, but 3.9 is not. However, are you going to update this project or not?

definitely - once i find time :)

How to add music to the WPI script by @razor12911. plz help

Also i checked other threads before asking for help but after editing the script i was receiving error so i am posting here plz help.

the script attached plz have a look anyone and add the code for music.plz

and pm me if possible. Thank you