when installing what are you choosing Install Linux along Windows
or Erase Disk and Install Linux
? http://blog.sudobits.com/wp-content/upl ... n-type.jpg
You should choose install along side Windows or Something Else
and create a two partitions: one for / and one for swap. Swap should be 2 times the size of your ram and the rest will be for your system files. Be sure to back any data before attempting to install,it's relative safe but you never know sometimes things never work as planned.