No Display after Windows Xp bootscreen. (fixed after system restore???

I'm using an ancient Computer powered by:
p4 3.00ghz
Inno3d Nvidia Toranado Geforce FX 5500
Asrock 775VM800
an 80 gb Maxtor hd
1GB kingston ddr 333
2 cd roms

i know this an old system but thats beside the point..

Anyways i was posting here a while ago then we had a power outage then when the electricity returned. I powered my spent 30 sec at post screen then after the xp bootscreen. my monitor gives a black screen with the power indicator flashing on and off. btw, there is no problem with the display in safe mode.

Troubleshooting i did:

1. reseated the video card
2. unplugged the psu for a while to remove power from MOBO
3. checked for any burnt smell and any signs of a short
4. checked the ram and for any loose connection

FYI

1. I did not overclock my computer
2. I did not change my refresh rate to a value not supported by my monitor
3. I'm sure that i installed the drivers correctly
4. The video card is still new (believe me)
5. I've been using it for a month with no issues whatsoever

HOW IT WAS FIXED:
by doing a SYSTEM RESTORE
I just want know how that happened? any ideas

test your hardware