Windows vista ultimate arduino sync problem

Ok I recently installed the Arduino 0022 on my vista ultimate desktop and it worked fine for the first time no problems but the next day after I shut my computer down the Arduino would not sync at all, windows found it and said it was on com 3 so in the Arduino program I checked com 3 everything was right but I still got the avr dude not in sync code. I have it installed on my laptop with xp and works great. Any ideas would be great. Thanks

When you open arduino with nothing plugged in, you do not see com3 .. but then you plug it in .. and com3 shows up .. is that correct?

Check to assure the correct board is selected.

Yea I have the UNO selected and it shows com 3 but yesterday I got it working and I don't know why sometimes it will work but today it won't upload to it

Someone else may need to chime in here - I don't have a Uno as of yet, so my advice using older boards may be flawed.