(Before you begin, empty your (recycle) bin. An AMAZING amount of stuff can lay around in there!)
One: I can say for sure that you need to have all that stuff remain on your computer.
Two: What's there doesn't really amount to much anyway.
Three: A good way to "make some space" is to delete long-unused installed programs. You'll need to do that manually, taking care to only remove things that you KNOW you no longer need. I suggest the following method:
1) Go to <Start> <Control Panel> and select <Program and Features>
2) Now in the <Uninstall or Change a program> list, select the top of the <Installed On> column to show the list from the oldest date at the top of the list. This can help you identify "crufty" programs and application that you no longer use.
NOTE!: Do NOT uninstall anything that you are uncertain about!In all likelihood you won't open up a lot of space this way, but sometimes it can clean up a LOT of old, unused stuff that you no longer need.
And finally, Four: I highly recommend you download a free copy of
Tweaknow Regcleaner. Install it and select the following actions:
<Quick Optimizer tab>
Everything EXCEPT "Optimize Internet/Network Settings"
and
<Windows Cleaner>
"Disk Cleaner"
"Registry Cleaner"