It depends on the virus and where it is, and, the tempature. But probably about three days from what I've heard. Whenever sick people come into my
home, I always wipe everything down with some lysol dis-infectant wipes. It's kept many a colds and flu out of the house...
5:00 Fox newscast here in Tampa had a Doctor on who is a specialist in this field.
The anchor asked this same question, specifically, and the answer was 2 hours.
Hope this helps.
Earlier today I read somewhere that the virus could live on hard surfaces around or more than 24 hours.
If this is correct or not I can not yet say. Let me come back here if I find some trustworthy sources of this, beside the MSN newspaper I read it
from.