I am currently using Microsoft Enterprise Manager 8.0.

This is what i have found in my error log:
2005-08-29 11:08:13.11 server SQL Server evaluation period has expired.

What should i do to get my SQLAgent to start working?

You might want to try purchasing a copy of SQL Server as your current license has expired.

Can i just purchase a sql server cd key? I do not wish to reinstall the whole database again. As i have a project going on and now i am unable to conitnue because of this. Is it possible? If not, is there any other way i can do that includes not reinstalling the database i have?

Yes, you should be able to purchase and get a key for it.

I have managed to solve the problem already, thanks for replying guys!