I tried updating my antivir in suse 10 and got this message
Warning: the file "antivir.vdf" is more than 14 days old
checking for updates

06.31.00.05 <=> 06.34.00.67 [vdf database, on-disk]
06.31.00.05 <=> 06.34.00.14 [scan engine, running]
06.31.00.05 <=> 06.34.00.14 [scan engine, on-disk]

error: can neither update the engine nor VDF files (no write access)

i then tried updating with xserver off on init3 - got a update disabled message.
What can i do to fix this?

The version of AntiVir that ships with SUSE is for commercial use. You will have to purchase and install a license to be able to run updates.
However, AntiVir offers free-for-home-use license. They have changed their website around a bit, so I can't tell you the links to the free license. You will have to register with AntiVir as a home user to get the free license to install and activate AntiVir. That license will have to be renewed every year.
If I remember correctly, getting the free license also involves downloading and installing the AntiVir Workstation version (which will update your current installation to the free version). Update should occur automatically.

no write access sounds like you need to be root to update.