I have a 40 GB hard drive and i used the whole thing for linux. I want to edit this size and make it about 30 GB so i have 10 GB for windows. Is there any way i can do this without loosing anything that is on my hard drive?

Also, is there any partitioning programs for linux?

Thanks.

My suggestion is this:
FIRST: make a backup of anything that you can't re-install from cd/dvd. Such as /home, /etc, and any apps you installed from other sources.
Second: look into cfdisk. I've used it on my SourceMage partition (it's sort of GUI and sort of command-line). It allows you to specify such things as:
a) make a partition bootable.
b) change the size of a partition.
c) re-write the partition tables for the re-sized partitions.

Some folks may recommend partimage. The main drawback of partimage is that the partition image saved via partimage MUST be the same size as the partition the image will be written to!

There are other options. www.google.com/linux is your friend. Search for them there.