can´t upload sketch on windows 7

hi, yesterday i received my new arduino mega and i uploaded some sketches. but now i cant upload anything. why is this happening? im running arduino on a windows 7 laptop. when i press upload, it just says UPLOADING to I/O BOARD and nothing ever happens. please help me :)

when you plug the board in - do you get the notification that hardware has been plugged in?

I had the same problem on my Mac and on a Windows XP machine. Things were working great with my Duemilanove... and then for some reason things just broke as described in these posts:

avrdude: stk500_getsync(): not in sync: resp=0x00 avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

I followed Doctor Wangs advice (a few pages up) of unplugging the board via USB, connecting it, and starting the upload (maybe I had hit the upload button a second before I plugged it in). My program uploaded and now everything seems OK. Really weird.

Good luck.