If so, these lines are to blame:

item: Remark
  Text=BACKUP is the variable that holds the path that all backup files will be copied to when overwritten
end
item: Set Variable
  Variable=BACKUP
  Value=%MAINDIR%\BACKUP
  Flags=10000000
end
item: Remark
end
item: Remark
  Text=DOBACKUP determines if a backup will be performed.  The possible values are A (do backup) or B (do not do backup)
end
item: Set Variable
  Variable=DOBACKUP
  Value=A
  Flags=10000000
end

Try setting DOBACKUP to B or removing these lines entirely.

Hi Edt,

I am not using any of the code above in my wrapper.

If you want I can upload the ipf file entirely ?

I am not using the BACKUP or the DOBACKUP variable.
I am using the _BACKUP variable, could this variable be to blame ?

IPF files are created by SMS Installer, which was licensed by Wise to Microsoft, but does have a few differences in functionality.
Can you confirm which version of SMS Installer you are using?
Also, attaching your IPF file as a ZIP would be helpful. You may need to do this to your first posting in this thread as I don't believe you can attach files to later postings in a thread.

Apparently when I open the ipf in notepad it says Document Type: WSE,  the extension is ipf.
Is that a problem ?

I have attached the file.

line 380 When I replace existing files,  the files that were present are backed up to the C:\backup folder,  while i don't want this

line 410, 411, 412  When I delete files, the files in question are backed up to the C:\backup folder.

Please let me know if anything is still unclear.
Thank you for your help.

I have had a look in your IPF file using a text editor, and there are no references at all to C:\BACKUP.
The only references I can find are many to C:\CABACKUP, but I am assuming that you would not have made a basic typing error like this in your postings.

What I can see, however, are a number of MSIEXEC operations when apps are being removed, etc, and it is perfectly possible that one or more of these MSI uninstall processes could be running a custom action which is backing stuff up to the C:\BACKUP folder.

There are two strategies for testing this. One is to remark out all the MSIEXEC calls and see if the C:\BACKUP folder is now unaffected when your code is run.
The other is to single step through the IPF code and check your C:\BACKUP folder after each command is executed.

Hey, that's not been done for a while - reading the documentation to find the answer.
It's so long since anyone tried that and I had forgotten all about it myself.

Yes, those predefined Wisescript variables are all listed near the end of the Wisescript Editor manual.