cannot restore inspiron 1318 from partition

I need to restore a trojan infected hard drive on an inspiron 1318.  i can get to the "repair the computer" using the F8 key.  A screen opens that shows "other user" then requests user name and password.  I KNOW the user name and password.  It will not accept anything.  I tried using "administrator" and no password and everything I enter is rejected.   I even went into bios and disaabled any need for passwords.  No luck. I have the restore CD.  The trojan is monopolizing my memory.  When I try to restore from the CD, it tells me that I do not have enough available memory to do a restore (for the temporary fiels)  Please if anyone has experienced this and knows the answer.... please share!!!!!