windows will not boot normally

Good afternoon folks..... Yet another problem.... My computer has developed a problem since installing a new power supply (antec 400w smart power, atx12v) to replace a cheap one I installed last summer (POWMAX 300W atx). I've done this several times in my short computer life and have never had any problems. When I power up the computer, it goes to safe mode only. All the hardware in setting/system are OK, no exclamation markers. When I restart system and select normal mode, computer acts like it wants to boot normally, but then goes to a blank screen (dark) with the wait sign waving. That's far as it will go. I've tried unpluging things one at a time and that does not work. So I put the old power supply back in and guess what.. the same problem. What could I possibly have done????? This computer was working perfectly before. This just blows my mind... Can anyone make any suggestions... My computer consists of wind98se operating system, Transend AKTA4 board, 512mb sdr memory, sound blaster live audio card, nvidiaGF3ti video card. Acer cd burner/cd drive and samsung dvd drive. This new PS is not a cheap one and would like to get my monies worth. I take all the precautions when working on computers. i.e. static and etc.

 

If you've removed and reseated the components, check IDE cables and power to the drives.
Double check that you have the keyboard and mouse in the correct places (hey, it sounds stupid, but I've seen so many simple things overlooked).
Can you boot to DOS and try scanreg /restore?

 

It has happened to me. I cleared my CMOS and restarted and back to normal.

 

Thanks for the replies..... I did check that all was plugged in both the pci slots and power plugs, etc..... I don't know what I did, but with the old power supply back in and still would not boot, a period of power off then back on seemed to fix this?????? I don't feel the new PS is at fault because of the brand/cost and quality. Would you re-install and if so what precautions would you take in addition to which ones I did???? Thanks

 

Sometimes a PSU and BIOS can get mixed up communicating.
Unplugging the motherboard plug, and powering up the PSU then shutdown, reconnect and everything will go again.
It's got something to do with the detection in the PSU of a hotkey bootup via the motherboard. Can be the sign of a failing PSU.
In your case, the capacitor in the PSU that allows for instant on, just needed to discharge completely to recycle itself.