My question is regarding this "C:\Windows\Installer" hidden systems folder on my Windows 7. I am sure it is present on Vista and maybe winxp too. This folder appears to contain .msi and .msp installers for the various software on my computer including windows patches. It is taking up significant real estate on my system. It is currently 1.63 GB and growing. I did a fresh format 4 months ago so in 4 months it has grown from about a few MB to 1.63 GB! Is this folder important? What is its purpose? Are the installers for backup purposes only? Can I safely delete them? I am sure most of you like me do not want unnecessary junk on your system and this folder appears to contain only installers for the software on your computer. p.s. the installer files inside the folder are renamed. You will have to right click, go to properties and then details to see which software the installer belong to.