Windows freezes and wont start successfully

Good day, i need a help. Im really out of my mind on what should i do with the pc here (1 monit0r & 2cpu) well its been more than a year i guess, that it was not used, And these cpu's are not responding well. I spend almost a week to switch hardware between them(hdd, power supply, dvd & cd rom(except for the ram cause they ar'nt the same physical size).Also, i reinstall the windows b0th (wndows sp3). And i figured out that their motherb0ard is at fault! So lets name it mobo1 and mobo2.

1. Mobo1
(asus P4GE MX mothrboard)
512mb ram, 40gg hdd
2. Mobo2 (compaq and i cnt see its model) w/ only 127mb ram, 20gg hdd

Mobo1
>when i on the pc, its mobo led lights green.
>the pc says: windows didnt start successfuly, a recent change in software or hardware may have caused the problem. Even i chose safemode, sm w/ netw0rking, sm w/ command pr0mpt, last known good configuration, n0rmal mode and also in advanced options it didnt starts, instead, it ends up flashing the blue screen error in less than a sec0nd where it says: windows shut down to prevent damage, also it says check for viruses and etc.. Techncal info: 0x0000007B (0xf993f528, 0xc0000034, 0x00000000, 0x00000000) and the pc automatically switches off, before i forgot i already clean it especially the fan.
>i dont know if what service pack was this but i guess this was sp2 before i installed the sp3

1. Any solution for this?
2. Do i need to update bios? If yes, how? If i cant seem to start it even in safemode!

Mobo2
>does not have built in led lights on it
>the pc starts but, later in the desktop it freezes in different location
>its still freezes in different safemode choices!
>it freezes when i open the c0ntr0l panel>add/remove hardware and pr0cesses in task manager
>i used this mob0 to reinstall b0th hdd, even though i only use 1 ram stick with 64mb
>already cleaned this mobo. But same results it Freezes
>windows xp sp1, thats what i saw before i installed the sp3 on it.

1. What would be the cause to its freezing?
2. Does it need to update first the bios before upgrading a new os?
3. Are these mobo's still have a chance and can be used?

As you can see these are old model though, i still want to use it, i have no ch0ice, the laptop was sold, cause my sis is buying a new one later in Feb. I cant find any enjoyment down here got no friends, and still dont know how to speak new language..