Does windows say you have 125gb left, and ubuntu says it has 1.4gb? Ubuntu is probably telling you how much space you have left on its partition, and windows is telling how much space is free on its partition.
If you can access your windows partition you can run the following command
at a command prompt and it will tell you some detailed information about the currently mounted filesystems. There will be several listed, but the ones your worried about are mounted at / and then wherever your windows partition gets mounted, probably in /mnt (I'm not ubuntu friendly, so I don't know their default mount location, sorry)