PSU ... Restart win ... SOS

[NambrVan]

I have:

asus p5k premium
4x 1g Gail Black Dragon 800 Quad
1x Maxtor Sata 200gb
1x Maxtor Sata 250gb
1x WD Sata 500gb
1x DVD
1x Sound Card
Intel 6750
Palit 8800gt 512
1x Flopy

With my chieftec 410w (2-3 years old) , I have random win restart, sometime when I eneter any game, sometime when work in win. Its very random. For example, I run 3dmark, sometimes restart is on 1st test, sometimes on 3rd. There is no cpu, mb, vga heating, all teps r normal. I disabled auto restart in win.

I started MemTest, and after 16 hours got 0 errors. Had no restart in memtest (dos).

Is problem in my PSU?
If it is, is ThermalTake ToughPower 600W W0103RE (Eurolink, Beograd | Prodaja računara i računarske opreme | Detalji proizvoda) good for my pc?
Thx 4 answer

[AMDPhenomX4]

It might be your Power Supply Unit.It probably cant power everything.Let me get the power calculator link. Link
And as power supplies age their capacitors degrade.A new PSU should be a Fix.