What can I remove from Win7 for small install size?

I have an ultrabook with a 18.6GiB SSD and a 500GB HDD that I will have just made a fresh install of Win7 onto. I installed Win7 onto the 20GB SSD in order to gain speed, and I will use the 500GB HDD primarily for data.

It's current state is: fresh Win7 install (result was ~2GiB free), then disabled hibernation (then 4.2GiB free). Default User Profiles ("\users") have been redirected to the HDD, but that does not change the 4.2GiB free SSD yet.

I have seen a few posts where people have reduced their installs to 6GB, but they seem to be tossing things out everything including Notepad and Windows Time, but I do not want to be that ruthless as I still want Win7 to function normally, but just without some of it's "bloatware".

Misc Notes:
-the Win7 install disc had SP1 slipstreamed into it, as well as all drivers (I used RT7Lite).
-I will install Comodo, Avast, VLC, Firefox, and Thunderbird, so I will not use the Windows Firewall, Windows Antivirus, Windows Media Player, IE, or Outlook Express.
-I apply all my patches manually, so I will not be using Windows Update (can it be deleted, and would that save any decent space?).
-I do not care about themes etc.
-I do care about security, and use "Group Policy Editor" for GPO, and "Microsoft Management Console (MMC)".

While I know how to turn off the features I do not use, I do not know which files to delete to save the space of the feature I am not using, so any advice on this would be greatly appreciated.

Lastly, if you know of large chunks of space that can only be saved by making a tweaked ISO with RT7Lite and doing a fresh install rather than trying to delete things after the install, please let me know.

I would use MSE with the Window Firewall which is perfected and nearly unanimously recommended here at the the home of Win7. No one here recommends Comodo - we've never seen anything but problems with it. Avast has bloated up and causes probs never seen with MSE.

Keep all Windows Updates current avoiding nothing except Bingware. These are vital performance and security patches which will affect how the OS performs and is protected.

Don't take it out on the best OS ever that there's only 20gb which is not really practical. We've squeezed it down to 32 gb to install on the caching drive which comes on some laptops, but 20gb is not really doable unless you install programs on the spinner which defeats the purpose of an SSD. But you can install most used programs to the SSD.

During beta we experimented with vLiting for size and performance. There is no performance clawback at all by removing anything, just unintended consequences. For netbooks there was interest for awhile to vLite (now 7Lite) out the Language and Drivers files for size but I've not heard anything about it for years and can't even find the threads which addressed this which means it has zero popularity.

Hi Gregrocker. Please don't take it personally that I do not want to use some parts of Win7, it is just my preference for more control and flexibility.
It is rather like installing a different stereo in your car. It does not mean you hate the whole car, just that you want a stereo with different features.

You are correct in that I will be installing lesser used programs to the HDD rather than the SSD (but of course this will not "defeat the purpose" of the SSD because the SSD will still be used for the OS functions and frequently used programs, making the system quite speedy in normal use).

Hello AddRAM. I want to keep System Restore as I find it useful (I can always clear out the restore points periodically to free space if I need to), and I have already turned off Hibernation as I mentioned in the OP, so unfortunately those will not save me any further space.

I am just looking to save space by removing Win7 installed files than I will never use. Some forum posts say they have PCs running with 10 GB Win7 installs (one even claimed to be below 6GB), so although I do not want to be as brutal about it as that, this indicates there must be some space to save.

I agree with gregrocker.

You are in uncharted territory when you start ripping out portions of Windows. The OS does not consist of independent modules that you can mix and match according to your wishes. It is possible to remove substantial portions of Windows code. But what important system services will no longer operate? And what popular Windows applications will not run in such an environment? No one can tell you, not even the Microsoft developers. The best anyone can do is make educated guesses, and such are often wrong.