whats the use of c:\windows\installer

U can delete them but it might cause problems when u'll want to change/remove the corresponding s/w from Add/remove components!

Actually Whenever we install some s/w, which use Windows Installer for installing itself, a copy of that installer is created in this folder, and its used when we change/remove the s/w from the system!

So if u r sure that U'll not need that file, u can safely remove those!

i would still advice u not to delete the folder. if u want some disk space use winxp's diskcleaner utility, remove systemrestore points or use freeware 'ccleaner'.

That folder stores msi installers. If you right click on those .msi files, you will get options such as install, repair, uninstall. That is what their purpose is.

If you want to reduce size of that folder, then you should 'Disable Rollback'.

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\Installer]
"DisableRollback"=dword:00000001
OR
[HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\Windows\Installer]
"DisableRollback"=dword:00000001

never delete this folder, when u install something which is windows installer, it caches the msp & msi files there for faster access later, & in case u uninstll it, it replaces all the files removed during installation back

this is a system folder, so better leave it as such, however u can delete any $patchcache$ folder inside it

Thanks a lot people.
I am not touching it. Let windows decide what to do with my computer as long as i am not affected. I have a decent free space in my hard disk.

Again, Thanks a lot dudes.