A user calls to complain that her computer is behaving erratically. Some days it functions correctly, and other days, it crashes frequently. Sometimes, the system won't boot at all. You open the system case and notice the following: Two of the mounting screws are missing from the system hard disk drive. The system uses memory modules from several different manufacturers with mismatched capacities. Several capacitors on the motherboard are bulging and have a brown liquid oozing from them. The chassis fan on the front of the case is oriented to blow air into the system. What should you do

The motherboard is the core of the computer. If the motherboard is oozing brown stuff, signifying that one of the sectors has been eroded or is about to disrupt, it needs to be replaced before further damage can be made.

The screws in the hard drive can easily be replaced.

As for the memory sticks, they will operate best if they were the same brand and the same memory size and hertz.