Computer power issue.. maybe?

Hi so My computer was working all fine and happy, but then one day I pressed the power button and all the fans start spinning and the red busy light came on, but the computer itself didnt actually start up at all. After flicking the power supply switch on and off a couple of times it started up again all fine.

It had this start up problem for a while, sometimes the fans don't spin sometimes they do, but flicking the power supply switch on and off untill i hear a kinda pop sound makes it work.

But now its got a little worse and sometimes it will just lose power while its on.
Another thing happened, my xp sorta completely stopped working, like I couldn't even open something like msconfig or even freecell, but non windows sorta things like firefox would work fine, so I was trying to instal windows 7 in a free partition in my hdd, but the computer kept losing power while it was trying to install.

So I got some compressed air and blew out alot of dust, put in some more ram and a second hdd and formatted the parition with xp and then i was able to install windows 7 without the computer losing power all the time.

But the weird power issue remains andd now my computer does just randomly lose power and it's even more flicking the power supply switch on and off to make it start up.

I'm just not really sure if this would be a power supply problem or a more annoying problem with my motherboard, and I would really appreciate some advice from people who know what they are talking about where I just kinda guess and hope >_<;;

So now I will supply the information about my computer so you can understand the kinda system I am using.

CASE:
NZXT ZERO BLACK
PSU:
Zalman ZM600-HP 600w
Motherbaord:
ASUS M2N-SLI Deluxe
CPU:
AMD Athlon 6000+ 64bit duelcore (AM2)
CPU FAN:
Zalman CNPS7500-AlCu-LED
RAM:
Corsair Micro TWIN 2GB (2x 1GB sticks) //added another 2Gb of random ddr2) ram after problem first started
HDD:
Seagate 500GB //added random 300Gbhdd after problem started)
SCREEN:
Samsung 206BW 22" widescreen
DVD Drive/Burnner:
Pioneer DVR-A12XLB

I also downloaded a program i saw that will tell you computer temperatures and voltages... but i dont know enouph to find the information super useful i got the program from http://www.almico.com/speedfan.php and here is a print screeny of the information it is giving me, I added this image as an attachment.

Please any advice or help is really appreciated,
Thankyou for reading and please tell me if i need to supply any more info

 

Hi

First off, STOP flicking the power switch on and off to "get it to work". You DEFINITELY have a bad power supply, and I'm not sure of Zalman's reputation, but if you're within the warranty period you'd definitely want to get it replaced. If you're not within the warranty period (should be 3 years from what I've read), buy a new power supply. Antec and Corsair make good PSUs, though don't go for their "budget" models.

A power supply can take other hardware components out with it if it malfunctions/fails, so the more you play with it, the more you risk damaging your other hardware.

 

Thankyou so much for the reply, next time I turn it off I won't try to turn it on ag untill i get a new PSU. Thankyou for the reccomendations for some good brands also. It's about 4years old so def not under warranty anymore, but I'll just get a new one.
Again thankyou so much, I hope i didnt hurt anything by flicking the power switch.