In regards to:

http://unattended.msfn.org/xp/space_saving_tips.htm

is there a way to tell if its safe to delete the language folder?

I guess I could move it as a backup and test it with Vmware, but are there any other quicker methods i could try?

I strongly suggest you still "try" just to be sure.

Even if I've seen somewhere that this is only required for real foreign language...

i have deleted the LANG folder, there is no harm to my system.

this is only required for East Asian language support, other foreign language still working.

and if u want install them later the system w'll ask for location of LANG folder.

yep... no problems here with removing LANG folder...

Deleting LANG gave no problem with Indic languages either.

Its safe to delete if you use only English.