Which files are safe to delete to increase HD space?

[CompCues]

One of our computers only has a small amount of HD space left and I'm trying to delete unnecessary files. It uses Windows XP Professional, 256 MB RAM, 5 G HD (the original 20 g HD was replaced), 1200 MhZ celeron processor, runs on a network with DSL. It's a Compaq Presario 5400US desktop PC. I've deleted or uninstalled numerous files, and run batch files to make space available, but there's still too few megabytes left.

It runs AOL 9.0 and AVG anti-virus 8.5 , but I want to see what can be deleted from folder(s). Other files listed in Control Panel:

• MSXML 4.0 SP2 (three times): KB 927978, 936181, 954430
• Pure Networks Port Magic
• Security Update Windows Media Player 9 (2006). (Windows Media Player is never used)
• Learn2 Player (Uninstall only)

There are many security updates listed. Can I safely delete Windows security updates from 2006? There are many of these security updates from 2008+.

Thanks.

[Ridgerunr]

This free program can get rid of many useless items...

[jdc2000]

A 20GB HD replaced with a 5GB? Time to spend $35 + shipping for an 80GB HD.

[DeP]

There are many security updates listed. Can I safely delete Windows security updates from 2006? There are many of these security updates from 2008+.

Not from add/remove programs. Delete them from disk.
The folders are under C:\Windows and start with $NtUninstall.
If you don't want to undo an update it's safe to delete those folders.

If you don't need restore points, you can delete those as well.
Rightclick My computer > properties > on the tab System restore check 'turn off systemrestore for all drives > apply. (Turn it back on, if you want)

Having said that, a 5 Gb is very tiny. My Windows folder takes up 3.8 Gb.
Don't expect a lot of free space.
You are better of buying a new HD and some memory as well.