I am trying to install an ATI Radeon X800 Pro PCI Express edition onto my new motherboard. My old mb used agp and my power supply doesnt have pci express power cord on it, so i bought an adapter. It has 2 power adapters going into the 1 pci adapter. my computer wont even turn on if i have both of the 4 slot power adapters plugged in and if i only plug 1 in my computer will start but go into a restart loop. can anyone tell me how to fix this please?

Try to boot into safe mode and uncheck automatic reboot in startup and recovery in the system properties. That might stop the loop. As far as the adapter goes, it probably can't handle it.

"can anyone tell me how to fix this please?" Get a new power supply that conforms to the latest ATX12V 2.x standard

Assuming you got the right wiring adapter, your power supply must also have enough capacity to be able to supply enough current to the PCI-e slots and the video card - bare minimum about 420 watts. You may be able to get away with a lesser PS if you don't use the PCI-e slots for a video card, but you must have enough capacity if you do.

We ran into this same problem at our effects studio. The standard adapters have one extra negative wire that causes the power supply to short out. The internal short prevention of the Power-Supply prevents it from turning on. You need to cut the middle wire that is across from the clip. See below for example. Note: This diagram is relative to the latch clip being on the top. ______CLIP______ :--G-:--G-:--G-: :12v+:xxxx:12v+: ---------------- The "--G-" represents ground pins and the "12v+" represents the yellow positive pins. The "XXXX" is the pin that needs to be cut or remove. It is not used by the graphics card and can cause a short. I hope this helps. You can find more information from the newegg.com user reviews. Read the reviews of this item for more info: PCI-E Adapter LINK: http://www.newegg.com/Product/Produ... Film-VFX Site: Green Screen Chroma-Key backdrop Supplies http://www.eefx.com #1 Source for film VFX and chroma-key green screen supplies