VMware, Virtual PC and VirtualBox do require modern hardware but it is recommended to use high-end and modern CPUs (1 GHz or higher is recommended) so you won’t see much of slow performance when running a guest system. More RAM is also recommended especially if you will run multiple guest operating systems. All of these programs can be installed on 32-bit or 64-bit editions of Windows and you can also install it on many distros of Linux.
The installer of VMware is 507MB which larger than VirtualBox (67.8MB) and Virtual PC (30.4MB). The required installation size for Virtual PC (36MB) is smaller than what VirtualBox (79MB) and VMware (150MB) will use.
All of the 3 programs will automatically install the network adapters. VirtualBox and VMware’s installation process is quick and straightforward like Virtual PC. However, there is more customization option during installation with VB and VM. If you are advanced user, you will be enjoying VirtualBox and VMware.