nspatel112,
I'm thinking the initial partitioning of this drive is what limited the space. If you want to use the ENTIRE 160Gb of this drive, you should be able to remove ALL parititions from it and install Windows on a single 160Gb partition.
Doing do will erase ALL data on all existing partitions, so be sure you have backups of any/all data on those partitions that you need to retain.
http://www.seagate.com/ww/v/index.js...&reqPage=Model
- John