You'll find Partition Magic does such things. Downside? It can cost as much as a hard disk that you could copy your OS and partition data onto one partition and then just keep the old drive as backup.
XP does NOT have this feature.
I have an Athlon PC running Windows ME and having a 20GB hard drive with 2 partitions, which I would like to merge w/o having to reload the OS or other software I have accumulated on it! I know that my newer PC with Win XP Home has built-in utilities to work with disk partitions, but couldn't find similar ones in Win ME. Does anyone know how I can do this, or do I definitely need a 3rd party software?