Lotta doubt. That will just not be the case... if it is a properly built, or name brand Power Supply.

Ok, so after taking raybay's advice about not changing anything on a Bestec power supply, I have decieded to change my crappy PSU.

So, I thinking of getting a Hiper 580W Type-M PSU as an upgrade.

Here are some more info on that PSU:
http://www.hipergroup.com/English/products/hpu-4m580.html

So, what to you guys think of this PSU, do you think its good upgrade?

Also, can anyone give a link to a good PSU installation guide, although I think I can install a PSU by myself.

1st off the monitor has its own power supply, and does not use from your power supply. so that program is sort of MISS LEADING.

Every device you have in your system is rated. check ea device.
and use the MAX. required. make notes on PAPER,
add all the required power in watts together. keeping the 5vt and 12vt seperate.
Power = Amp X Volts. ( actually P = I x E) it is best to always figure the MAX used... on 5Vt and 12Vt. then check your power supply. If your Bestec says it will handle then WTF.. try it. requardless of what others say about your items - Honestly "If it works then don"t fix it " ...
personal opinions mean very little in the real world.
Apevia is about the same as Bestec... and Both NVidia and ATI are having driver problems with Vista ...

Thanks, for your advice Frank, but I think raybay is right in saying that a Brand PC with a Bestec PSU is almost proprietary system and thatBestec PSU doesn't handle change well.

I think raybay is right, because my previous PC, a Packard Bell, originally had a Bestec or someother crap PSU and when I upgraded to a GeForce FX 5700 card on my previous PC, the PSU started making a weird siren type noise about a month after installing the FX 5200 and the PSU was replaced by a technician, since that PC was still under warranty.

However, since my current Compaq PC's warranty has expired, I can't risk having this PSU crash, so I might as well upgrade it before I upgrade my graphics.

WTF here's another opinion, since everyone is entitled to one. Since this whole exercise began about a video card/psu comparison the quickest way to figure out is to find out the total wattage on the psu label for 12v rails and divide by 12, then check the card's rating. That is if you believe everything you see, I know I don't, WTF

kpo, can you tell what you think of this Hiper 580W Type-M PSU I am thinking of getting.

30amps on the 12v rails. Very good. This is going on these specs though:
http://forums.guru3d.com/showthread.php?t=205763

Just my opinion but they seem pretty reliable.