Vista - Unable to log in

Hi,

I have just installed windows vista on my work laptop that I travel
around my sites with. I wanted to try it for a while when I was away. Because
I have allways logged on using the Administrator account and have currently
have no access to the domains I cannot log onto the local machine. What do I
do! I need to activate soon before it locks me out and It will have locked me
out before I return with access to the domain. I could also do with access to
the machine to get my work. The other anoying thing is that Vista has
destroyed GRUB so I cannot even log into linux to get any use from my
machine. If anyone can help I would appreciate it as this is going to cost me
lots of money if I cannot maintain the networks I administer.