Why do programs NEED to be installed on C:\ drive?

[quinriva]

Why is it that so many programs insist on being installed on the system drive? For a long time I have had an 8 GB system drive partition, with a heavily customised nLite version of Windows XP and it seems that every time I install a new program I need to delete files from my system drive.

I know 8 GB is not much, but it should be well and truly enough for an operating system especially considering my page file, my temporary directory and my documents are all stored on different drives.

One folder that always seems to balloon out astronomically is the ~\Windows\Installer folder. I assumed this folder just contained the installation packages for files that I had already installed, however upon deleting it I lost all my icons for Microsoft office (Excel, Word, etc.) - as a side note any idea how I can fix this? Last I deleted the folder it was 2 GB, and within about two months it is already back to 650MB.

Although my documents are on a separate drive, various applications still insist on using ~\Documents and Settings\username\Local Settings\Application Data or ~\Documents and Settings\username\Application Dat to store enormous amounts of data. Call of duty world War decides it wants to install or custom maps and mods here, similarly for CitiesXL - and with each custom map being 40 to 50 MB this can easily balloon out to 2 or 3 GB.

~\Documents and Settings\All Users\Application Data also gets bloated with huge chunks of data from Dragon NaturallySpeaking, Solid Works 2009, and Microsoft Help. Not to mention that ~\Program Files\Common Files directory is over a gigabyte.

Basically I have two questions:

How were forced programs to install in the application directory rather than bloat up my system drive?

At a record or registry changes made by program at installation time, so that if I reinstall Windows I only need to update the registry not reinstall the entire program.

Yes I know the easiest way would be to increase the size of the system partition, however that would defeat the point. I reinstall Windows quite regularly, basically any time something weird happens I cannot diagnose I just reinstall Windows - it only takes about 13 minutes. Secondly I eventually want to move my entire system drive to a RAM Disk, so obviously anything like an 8 GB becomes quite difficult.

[submix8c]

Go here and read post #2. I don't know if you can "move" the Installer folder as it (usually) contains the icons and MSI sub-sets from the installation (e.g. the "options" you choose) and are "required". Also, read this for a warning.

As for the other "bloat", use CCleaner, since many files can be safely deleted by it (install it, run it, and look under the Applications tab for which ones it recognizes). This proggy is widely used and recognized. And a warning, watch out for the other options within, since they may/may not cause problems when used (i.e. the Registry clean section).

Just a small bit of assist... anyone else?

Edited October 25, 2009 by submix8c