A highly respected Global Moderator, at a highly respected forum (BleepingComputer) wrote the following, when asked almost the same question as you. And I quote quietman7 ....
"FixMeStick claims to be an external hardware based device which can remove malware that cannot be removed by software anti-virus programs.
From what I have read that claim is somewhat misleading. FixMeStick is a bootable USB device which uses scanning engines from Sophos, Kaspersky, and VIPRE...it is primarily intended to get a computer to a more stable state so that you can use your existing anti-virus and other security tools to complete the disinfection process.
FixMeStick's home page includes a note at the top by PC Mag which indicates it is "extremely easy to use". What they fail to mention are the following comments also provided in PC Mag's review of their product...
Cons
Can't disinfect virus-infected files, can only quarantine them. Quarantine of system files rendered two test systems unbootable, requiring full undo. Can't handle malware traces in Registry. Alleged removal failed to prevent several detected rootkits from running.
Collateral Damage
FixMeStick can be a bit heavy-handed, wiping out files that it shouldn't. When its engines detect a valid file infested by malware, it can't disinfect the file back to its original status. All it can do is toss that file into quarantine. If this happens to an essential Windows file, you may be hosed.
There are many free LiveCD/Rescue CD utilities which can do the same thing so I see no reason to purchase this product. "
http://www.bleepingcomputer.com/forums/t/545375/fixmestick/#entry3456066
I would start by following the instructions and (FREE) tools Grif offered, as Bob eluded to in his post. Many of those FREE tools should help you with whatever problems you're experiencing. IF not, kindly post back and let us know.
Best of luck,
Carol
Note: The bold highlighting is mine.