Hi Neil
I suspect you will want to keep some of the above/
Adobe Reader allows you to read / print PDF documents
Compatability Pack allows you to open / edit files from newer versions of Office
Java - there are applications and websites that will not function without this being installed
J2SE is also linked with Java - you can usually remove the oldest Java version.
Microsoft Office Powerpoint - not needed but if you do Powerpoint slide presentations then you will want to keep this.
Microsoft Works - again not needed. This is an old version of Office.
Realtek .....Audio Driver - this is linked to your Sound Card
Live Update could be linked with Norton AV
Inter Video X Pack - Connect with DVD supposed to improve picture quality
None of the above are essential - with the exception of Java which I would recommend that you keep.
You could also try Disk Cleanup
click Start, point to All Programs, point to Accessories, point to System Tools, and then click Disk Cleanup.
It will analyse your system and tell you how much space it will reclaim - you need to OK this.