What version of Windows is now installed, and was this system upgraded from a Win9x system? Some if this looks like leftovers after upgrades rather than clean installs.
If this system had some serious file corruption, some of those folders may be in the wrong location if their parent directory was corrupted. e.g., C:\Program Files\Media Player\multimedia files could become c:\multimedia files if the Media Player directory entry was corrupted.
c:\MCPP
Don't know what this one is so I'd leave it and do some research. First thing I found for those letters is Microsoft Communication Protocols, but didn't dig deep enough to see if that uses this folder name, or where it should be located, e.g., Under Windows or Program Files\Common Files
c:\multimedia files
Safe to delete if you don't need it's contents. This could be a misplaced folder from some media application, and should actually be under Program Files someplace.
c:\swsetup
This contains the installers for applications that shipped with the system. HP computers use this folder. The installers are run the first time you try to use a program. Safe to delete if you don't need to use/install any of the preinstalled applications. I'd back it up on a flash drive/DVD first. It's possible (but unlikely) that some applications may keep some of their files here to save space. They would cease to function if this is removed
c:\perflogs
Don't delete
c:\IO.sys
c:\MSDOS.sys
These two are used by Win9x systems. If this is Win2K or later and not a dual boot system you can delete these
c:\user.js
Firefox can use a user.js file to set user preferences instead of using the about-config dialog. This would usually be in the Firefox profile folder. Could have been placed here due to a corrupted directory, or someone may have copied it here for a backup. Open it in Notepad to see what it is. Probably safe to delete.
c:\autoexc.bat
Not used in win2k or later, though Win9x programs may complain if it's missing
c:\windows\system32
Do not even think about deleting
c:\documents and settings
Do not delete, symbolic link for pre-Vista programs to use. Though it's possibly a real folder, left over from an upgrade from Win2K.XP See below to check
c:\users\public
Do not delete
c:\users\me\my documents
c:\users\me\documents\my music
c:\users\me\documents\my pictures
c:\users\me\documents\my videos
If running Vista or later (with a C:\Users folder you are), these 4 are symbolic links so that programs written for XP and earlier can work. Do not delete.
You can verify that these are symbolic links by opening a command prompt (SHould open at C:\Users\me) and type Dir /AD
These will be flagged
rather than
Do Dir C:\ /AD to check the c:\documents and settings folder
HKLM\SOFTWARE\microsoft\windows\curren…
Without seeing the entire key, I'd have to say don't delete
config.msi is not in the list, but is safe to delete. It will be recreated if necessary. It's a temp folder used by the Windows Installer (formerly MicroSoft Installer, hence MSI), but it doesn't delete the folder when finished.