The simple rule, get the fastest most powerful computer you can afford.
Intel i7 multi core 3+ GHz CPU Or AMD High end CPU (3+ GHz). Currently Intel is on top of the speed demons.
Pick one near the top of this chart.
http://www.cpubenchmark.net/high_end_cpus.html
Fastest GPU you can afford. Minimum of 1 GB of on board RAM.
Pick one near the top of this chart.
http://www.videocardbenchmark.net/high_end_gpus.html
Windows 7 64 Bit OS.
At least 6 GB of Ram 6-16 GB recommended. Fastest speed. Triple channel or Double channel (depends on your CPU architecture).
Plenty of Hard drive space 1 TB and up. Hard drives are the limiting factor for computer performance. 10,000 RPM is the fastest.
For Powerdirector, there is a big question about using Solid State Drives, Not enough free space on many of them.
Powerdirector needs about 100 GB of breathing room on the OS drive.
BluRay Burner. (if you have a BluRay burner, you do not need a DVD burner). BluRay Burners can burn and read all current disk formats.
External Hard drives for backup and external storage.
Ports: USB 3.0, Firewire, e-sata, ???
Yes, to all of the above. e-sata not necessary
Some USB 2.0 ports, there is still a lot of USB 2.0 stuff around. Such as Keyboards, Mice, Printers and Scanners.
Monitor: Your choice, Prefer Wide Screen 1920x1080.
Carl312: Windows 10 64-bit 8 GB RAM,AMD Phenom II X4 965 3.4 GHz,ATI Radeon HD 5770 1GB,240GB SSD,two 1TB HDs.