Can my machine be salvaged?

I have major problems, but before I waste your time and mine, I wanted to ask that basic question. I have TrojanDownloader, CWS, and Smitfraud viruses, all contracted seemingly at the same time. All of the fixes I see require internet access from the affected machine, but the lack of access is part of my problem. My browser is hijacked and so is my desktop. Is it likely that this can this be fixed without internet access? I am running XP w/Service Pack 1 due to some industry specific software and some memory issues on my old compute. I would throw it out, but the backups are not current enough to ditch my machine. I have learned more than I wanted to know about how viruses work. And although I am impressed with the design, I am screwed without some help. So, I am back to the basic question. Is fixing my machine doable given the constraints? I would appreciate your thoughts.

 

Thank you for the quick response. I think that the problem is fixed. I paid Symantec their $99. This was only possible because I followed your instructions before posting and somehow regained access to my browser/internet. So, you were helpful and instrumental in getting my problem solved.

So far, so good. I am confident that you could have solved my problem, but the time I would have needed to commit is not available. I hope that it is fixed, but if not, I'll be back begging you for help. Thanks again for getting back to me and your help.