Compaq Evo N110

Hello, I've got a little problem with this one. It is an old laptop and it has XP on it. But the problem is that it shuts off randomly. I guess it will be the overheating problems, because when I let the laptop turned on and doing nothing, it is fine, no random shutting off. But when application is launched, then for a short time it will turn off. I tried to clean the laptop, all of inside it, but didn't help. I also tried SpeedFan: when I launch it, it shows an error about some "Kernel32.dll" missing. I click OK and it will launch, showing the CPU usage. But when I look on the temperature, it is just showing 50 Celsius all the time. I noticed that in the top corner of SpeedFan is some error:
Scanning VIA SMBus at $8080
INFO: unable to use VIA686 sensors (bad I/O BASE)

So then I tried Sistem Information Viewer, and the same issue happened: SIV shows the same frozen 50 Celsius just like SpeedFan.

I also tried the BIOS settings to change overheating temperature, but there isn't that option.

Pls help me guys, I'm running mad 'coz of this.

Edit: yeah and SpeedFan doesn't show anything just that "frozen temperature" and CPU usage, thats all, it can't recognize any fans and other things

Edit2: ok, I tried another program, HWMonitor, the same problem: he is showing 50 Celsius, too.

Maybe some drivers are missing? I mean that ACPI thing, I don't know what it is, but none of programs can recognize anything...