Another strange problem with an almost-new PC.

Another high-end PC, that was taken back to the original manufacturer (a long distance away) twice… first to fix a faulty video card and power supply, then they are unable to fix this strange computer slowdown.

The PC uses an Intel mobo, a quick, late-model NVidia display card, a quad-core intel CPU, a WD5000AADS drive, W7-64bit, and a good power supply.

Its only got WoW and Norton running on it.

Everything is less than 6 months old, so there shouldn’t be any problems.

Whats unusual, is that the system boots normally, and at some point, will suddenly start running very slow…

I also note that the hard drive light is on – solid, while the slowdown happens.

The only other symptom is that the PC is “usually” very slow to shutdown… about 5 minutes… where I would expect about 10 seconds!

So, my first guess is that its a hardware fault.

I run various RAM tests (including the built-in W7 RAM test)… no fault after an overnight run.

I look at the hard drive SMART settings: everything looks normal… a clean bill of health.

Next: stress test the Video card and the CPU… but the stress test runs normally.

OK, what about the W7 event viewer.

I can see the graphics card fault from about 2 months ago, but the only other error is a warning that the system took a long time to shut down… but no specifics.

Next, I replace the video card… but the slowdown is still there.

At one point, while trying to start the task manager, I get the following error:

Failure to display security and shutdown options…  The logon process was unable to display security and logon options when Ctrl + Alt + Delete was pressed.

Now thats a doozey! It must take a lot to stop task manager from starting!

A virus scan finds nothing wrong.

So I try updating the BIOS. Nope.

Ah! the jokers who setup the PC installed W7 with the hard drive in IDE mode.

I switch to AHCI mode, and everything looks fine for a while, but the slowdown soon re-appears.

I start clutching at straws, and disable wmpnetwk.exe (it seemed to be using a lot of CPU at one stage).

On a forum somewhere, I see a vague mention of replacing a faulty drive…

I figure: its worth a shot… even though the drive doesn’t give the typical signs of failure, many things are pointing that way.

So I clone the 500Gb WD5000AADS drive to a 250Gb Seagate.

The clone process works perfectly (many faulty drives are just not cloneable).

After installing the 250Gb drive, the slowness just disappears!

I am completely amazed that a drive can have such a “quiet” fault, that its almost impossible to test for it without first replacing the whole drive.