Im not sure why but this tab is missing. can someone shed some light on this?
You will not see it if you are not logged in as the vendor.
To set the vendor first find your Joomla User ID - see this is in Joomla User / User manager.
Then in VirtueMart go to Configuration / Shop and "Enable database Update tools"
Then got to Tools / Tools & Migration and open the Migration tab.
Beside "Write here the new store owner id" - enter your Joomla user ID and click on the "Set store owner" button.
Right I did that and the general user information tab is still missing.
Alternate way to set vendor is to open the database in phpMyAdmin and look at table ###_virtuemart_vmusers The user_is_vendor should be set to 1 for the shop owner and also set virtuemart_vendor_id to 1.