My computer is infected. The name of the virus is Win32:Agent-LNK Wrm.Please help?

U know that I've answered many of ur queries.But now I am in danger.MCAFFEE NORTON AVAST etc antiviruses, many anti spywares and anti rootkites has detected it,in C:\WINDOWS\system32\drivers\smtpdrv.sys , and deleted the file smtpdrv.sys successfully.But in the next system reboot whenever internet is connected the file came back.As a result many emails[spams] r send to different addresses, and my network usage is incrasing.The simplest of all answers is to format my pc,but believe me i am not in a condition to do that in which case i will lose many vaable data.Also my printer is printing the doent proprties like file name,path,owner,total editing time,time of printing etc. before printing the doent.Are both the problems interrelated?Please let me solve both problems by answering as quickly as possible.Otherwise it will be too let.help!!!please........