if you are taking about

c:\windows \installer directory then

You can delete what ever is in there.

safe to delete the entire folder if you like

This link should help you out.

http://blogs.msdn.com/heaths/archive/2007/01/31/how-to-safely-delete-orphaned-patches.aspx

I think that directory is required and is used by the msi to 'self repair', etc

It has the msi files in it,

as i mentioned earlier , if you want to remove msi files not associated with your system

essentially you download the Windows Installer Cleanup Tool from Microsoft which comes with a command line utility called msizap.exe. After installing the tool, run cmd prompt.

C:\Program Files\Windows Installer Clean Up\msizap G!

And it will automatically remove any .msp files that are not registered on your system

We have some older servers that have very limited disk space, so I am looking to clean up whatever I can. and the directory C:\Documents and Settings\All Users\Application Data\Symantec\Cached Installs is over 120mb, so I wanted to see if I could remove any of the files there.

Perfect. Thanks Rafeeq

Have a wonderful day !