I recently downloaded Acrobat Reader 5.1: a 13 MB "exe" file. When it finished downloading, I double-clicked the file, and it installed the software in my C:/Program Files.

However, I thought I could delete the original downloaded file (which was called Acroreader51_ENU_full.exe and which I saved on a separate partition) because I assumed that it was just an "installer" that wasn't needed anymore (as was the case with other software I have downloaded).

However, when I tried to delete this file, the system wouldn't let me. I received the message "Access denied." Does this mean the file is necessary for Acrobat Reader to work properly?

I tried moving the file to another disk, but that would not work either. I also tried copying it, but it doesn't appear to copy everything (many properties that appeared in the original file were absent from the copied version).

I thought that the downloaded installer file - even if it is an .exe - was not needed anymore once it did its job and installed the software. Are some "installers" different? Can someone enlighten me please?

P.S. I was having trouble downloading the file Acroreader51_ENU_full.exe in Windows, so I tried doing so on my Mac (which worked). I saved it to a "shared folder" (a folder which the PC and Mac share). I never had problems moving or deleting files from this shared folder before, but could it possibly be a problem this time? (Maybe Windows thinks I don't have permission to move an .exe file...)