PC freezes before welcome screen

about 90% of the time i boot up my PC it freezes right before the welcome screen (the screen where you log in) all i have to do is press the restart (the one on the case) button and then it always boots up. i have about 4 + a guest account the PC. i have AVG FREE and zone alarm FREE in the startup menu + some drivers and the normal windows procceses.

oh and on another note how do i keep AVG from starting a complete scan when i start windows.

 

ah thx for the AVG help and my system specs are in my sig

 

the system is a few years old. although its been reformated and had a clean install of xp several time. i think the last clean install was about a year ago. i havent tryed the cntl+alt+del yet. i will try that the next time i am on that pc.

 

oh noooes could it really be the PSU? how? and no i dont have a spare PSU

 

ok here it is

 

Does it happen frequently, when ye boot into safemode?

 

it hasnt happend the last few times i booted up. i guess my pc is just tempermental

 

It is freaking hard trying to type, when the cat wants attention.

Okay.

In safe mode (this is a test, btw). Click START, then RUN, then type in msconfig (press enter).

Check the radial box "selective startup". Then uncheck "load startup items.". Press ok, yes to reboot.

Does it boot normally now?

If not, then ye want to go back into safe mode, run msconfig again, then go to the services tab. Check the box, "hide all MS serivces", then click the box, "Disable all". Press OK, then yes to reboot.

MSCONFIG is merely a troubleshooting tool, not a fix for issues.