A good answer might be:

if (  speed <= 800  ||  memory <= 128 )
  System.out.println("Reject this computer");
else
  System.out.println("Acceptable computer");

The following might be an even better way to write this code fragment:

if (  speed > 800  &&  memory > 128 )
  System.out.println("Acceptable computer");
else
  System.out.println("Reject this computer");