If you actually want to live longer (not to mention forever) then there is a number of problems to overcome. First, the idea that uploading you to a computer is rather silly. Yes one could theoretically get all the info in there, but how do you upload the ego?
Rather, if one wants to live significally longer then there is a number of medical problem that have to be solved:
1. atherosclerosis
Basicly that your blood vessel gets a slowely thicker layer of fat on the inside, we can not stop it happening (or well you could exclude saturated fat from your diet compleatly, but that might have some side effects and I am not sure if it would actually stop it anyway)
2. mutations (thus curing all forms of cancer)
When your cells divide it sometimes happens small error and thus you get some cells who, while working semi properly, does not preform like it used to. It could be better (evolution) or you could be out of luck and get cancer. Anyway, if enough error happens then your body won't cope with it anyway and you will die.
3. micro-organisms
4. Hayflick limit
Basicly we have these small things at the end of our dna which decides how many times a cell can split, it gets shorter in every new cell and at the end it won't split anymore. Interesting note is that cancer cells avoid this somehow.