A long time ago I wrote this and posted it...

Code:
#include "XP.h"
#include "WinNT.h"

void WaitCrashThread(void);

int main(void)
{
	//bootup
	Randomize(ERROR_MSGS); //WinXP does this at BOOT! Neat!
	UseMem("75%"); //improvement!
	Boot(WinNT->XPShell);
	DumbDown(WIN_NT);
	LockOut(USER_CMDS); //only during boot though, right?
	if(SystemSweep(PhysicalDrive, "erroneous") == 1) //oopsie!
	{
		SysBeep(1);
		printf("possible error found on drive %s - reformatting.\n",PhysicalDrive);
		Format(PhysicalDrive);
		if(USER_FRANTICALLY_BASHING_KEYS)
			StallSystem(50);
		printf("There we go, all clean");
		Reboot();
	}
	else //continue loading XP
	{
		Release(USER_CMDS);
		Load(PrettySkin, BUTCHER_COMPRESS);
		if(!UserLogin())
		{
			LockOut(USER_CMDS); //shouldn't ........ed XP off!
			printf("Bad Boy!\n");
			while(1)
			{	
				Reboot();
				Crash();
			}
		}
		Play(Load(AnnoyingStartupMIDI), MAX_VOLUME);
		LockOut(COMPETITOR_APPS); //including ZoneAlaram! Take that!
		if(SystemSweep(ALL_DRIVES, "competitor) == 1) {_unlink(Found);}
		Load(WIN_NT::XP_CORE) //slipped in a SMALL touch of C++
	} //Great, done booting up!
	Start(ALL_APPS);
	Start(UNWANTED_APPS);
	Annoy();
	Display(COPYRIGHT);
	Annoy();
	Display(COPYRIGHT);
	if(!Register)
		KillComputer(TOTAL, FRY_RAM, MELT_CPU);
	Display(COPYRIGHT);
	if(Closed(ANY_APP)
		Restart_App();
	Call(WaitCrashThread());
	return 666;
}

void WaitCrashThread(void)
{
	Wait(30); //one month
	Crash();
	LockOutEx(USER_CMDS, FORCE_REINSTALL);
}