one partition but no C visible

I have a virus and cannot see C. I tried using Uneraser for dos and it shows my C drive as a logical drive and it also shows 2 additional partiions one being fat 16 and the other fat 12. When I use fdisk it only shows a number 1 next to my ntfs drive but no letter? I dont want to format due to my cdrom not responding. This is a HP Pavillion ze1110 Laptop with XP home. I tried fdisk /mbr no luck, I tried creating a primary, when i run fdisk it shows the new partition with C and the ntfs partition as 2 but with no letter??? I can boot into XP with a new primary partition, but it gives me a passoword dialog box cannot go in. I tried safe mode with password but will not go in. If i clear user and passowrd it starts showing my background but then it logs off?? I tried command console but no password to enter. Any thoughts?