The Mana World Forums

the last times i have clicked the mana world my computer has rebooted

I'd guess at hardware problems.

and my BIOS password disappeared

Thats definitely a hardware problem. Check your fans, the CPU might be overheating.

Dammit someone noticed our special malware-tmw version with which we want to take over the world.

As Matt pointed out, there is a multitude of malware (viruses, worms, trojans, etc.) out there which are well capable of making your system unstable or even modifying your BIOS. Even on the fly. Once you figure out (scan, disinfect, see the report) which did it, you might also want to reinstall your operating system and reflash your BIOS.