Answer:
boot the computer from the windows installation disk and run startup repair
Explanation:
Based on the scenario being described within the question it can be said that the best option in this situation would be to boot the computer from the windows installation disk and run startup repair. This will analyze all windows files and clean up any files or malicious software that does not belong in order for the system to be able to correctly boot into the operating system. Then from inside the operating system you can run a full diagnostic of the system.
Well, you didn't say what language, so here's in Java:
public static void PrintShampooInstructions(int numCycles)
{
if(numCycles < 1)
System.out.println("Too few.");
else if (numCycles > 4)
System.out.println("Too many.");
else
{
for(int i = 1; i <= numCycles; i++)
{
System.out.println(i+": Lather and rinse.");
}
System.out.println("Done.");
}
}
And also in an image, in case you can't really see it