Is there any way to make a linux root partition (/) bigger?

Curenty i running Fedora Core 3 on 5gb. And after 3 day's its compete full. (today started 'yum update' and i had 0kb over). Have deleted some /var/cache/* folders. Now have 600 mb free. But have made 5 gb free on my windows partition for linux. So now i have: 5gb linux uses and 5gb 'free space' on my hard disk. I want to make they come together. Is there any way to do that?

And if it isn't. (and i have to reinstall linux). Is fedora a good chose? Of do i better install somting else?

I tested yet today many partition tools but none was abele to merge the free partition and te lnx partition. Tested ghost 2 to make an image of the partition but ghost crach eatch time and give strange errors.

Look into GNU parted (QT parted is a descent interface to this). It should be able to perform a merge of contiguous partitions.

well if you can format that 5 GB free partition to reiserfs or whatever, then you could copy everything inside /var into it and edit your fstab file to mount the partition onto /var. or something similiar, break up the 5 GB partition into whatever, as 5GB just for var is kinda big, unless you are running some type of server.
Linux partitions can't be resized after the fact unless you are using LVM, which your are not.

Linux partitions CAN be resized after the fact: just not easily, and not on a running system. Use parted and ext2resize or resizereiserfs (I believe those are the names). I have resized reiserfs without a problem.