Computer only recognized as Guest

I have 5 computers set up on a network (mainoffice). The computers all run windows xp with sql server. The office shares a business contact manager database that is stored on the primary computer (call it comp 1). Several months back I believe one computer was attacked by a virus that affected that machines sql server function. Since then, the affected computer (call it comp 2) has not been able to log on to bcm (interestingly enough, Microsoft security essentials also failed to operate on computer, after several days with MSE tech support accessing my computer, they finally just removed MSE and installed AVG, just a side note though). I believe I have traced the issue to the SQL server on comp 2. When I try to start SQL service (MSSMLBIZ), it fails unless it is set to local system (when issue first started I was getting a blue screen when comp 2 booted, I believe because SQL was set to auto and networkservice, by changing mssmlbiz start to manual and logging on as local system I have eliminated that issue, or at least sidestepped it for the time being). I can run BCM locally on comp 2 when I do this, but I can not access shared database on comp 1.

I have been working like this for a few weeks after trying for hours to remedy the SQL issue. Just recently I noticed something that may or may not be related. Comp 1 recognizes comp 2 only as guest (all other computers on network are shown by correct names, and I have reset the name on comp 2 several times after noticing this). When I try to grant access to the BCM database it shows comp 2 as guest. When I print remotely from comp 2 it shows up in comp 1's queue as guest.

Any help or suggestions would be greatly appreciated. I have tried everything I could find in searching about this issue, but none of the existing fixes for SQL have worked for me.