My Dell Latitude D600 running windows XP boots and when you insert a flash drive or any external drive you hear the sound and sometimes it displays while trying to boot and then hangs at the windows loading screen, but when it doesn't display, it boots fully. and also once it displayed and booted completely and while i was using it, it hanged.

Graham Godrules, March 2012

I forgot, if you still opt for a laptop, chose one with a DISCREETE video card.

You absolutely DON'T want ANY integrated video using shared RAM!
With an integrated video, the CPU must wait whenever the GPU need to access the part of RAM that it's been located, as it uses part of the main RAM as video RAM and the GPU can't wait without suppressing the display.

For the a similar reason, don't use any USB monitor. Streaming the video signal through the USB bus also mean that the video signal must travel on the main system data bus.

Electro, March 2012

Heavy gaming means desktop with some beefy PCIe video card. A multicore CPU is a definite plus as is a copious amount of RAM. You will also need a 500 to 750W PSU. (a 1000W PSU is overkill and only good for bragging)
Need good cooling!

Autocad, and about every modelers and graphics applications don't rely on the graphic card that much, they do most of their work on the CPU and main RAM. They almost only use the video card for the preview.
Multicore (4 to 8 cores) high end 64 bits CPU running a 64 bits OS is a must. Also, as much RAM as you can afford. With a 64 bits system, you are no longer limited to 4 Gb of RAM, you can have 24 Gb (triple channel with 3x8 Gb sticks) and way more...

This apply to EVERY modelers and ray tracers, although there are presently some GPU based ray tracers, they are still mostly at the proof of concept and alpha stage.

I don't know Revit, but as it's another architectural application from Autodesk, it's demands should be similar to Autocad's.

Recomended, not minimum, hardware requirements:
Microsoft Windows 7 64-bit Enterprise, Ultimate, Professional, or Home Premium edition
Intel® Core™ i7-2600 (or later) quad-core (hex or octo-core if possible) processor (3.8 GHz, 8 MB cache ) or equivalent AMD processor
16 GB RAM (or more)

Electro, March 2012

Thanks Electro, what system do u think is the best for playing heavy games like NFS, PES, etc and for using softwares like Autocad and Revit.

Graham Godrules, March 2012

Can you boot if the external drive is connected BEFORE you power up?

Try booting WITHOUT any external drive connected and wait untill after Windows have completely finished starting before reconnecting the drive.

If it freeze after some time using it, you may also have an overheating isue. Make sure that the air vents are free of dust and any other obstruction and that the CPU fan is working properly.

The Dell D600 was made around 2003. It's quite old. There may be a failling component on the motherboard itself, like the USB controller. If that's the case, you have no choice but to get a new computer, as it's probable that several other components are also reatching the end of their usefull life.

Electro, March 2012