High CPU usage ... it used to be fine, but no more

I returned home yesterday after traveling for Christmas, and I'm suddenly having a problem with Kontakt 5. (FWIW, I use Vintage D and the Galaxy Steinway and Vienna Grand pianos.)

I'm getting VERY high CPU usage.

In simple melodies with pedal I get occasional clicks.
With more complex music I get moderately high CPU and get lots of clicking.
At very high CPU I get mush/crush sounds.
When the CPU gets pegged at 100% I get dead silence ... until it settles away after a few seconds and the sound returns. (This happens on fat chord runs with pedal.)

What's odd is that I NEVER had this problem before. And I've done nothing to change the computer.

The laptop is a Core Duo 1.7 GHz, 2 MB RAM, Windows XP. I use a Presonus Audiobox USB sound card/MIDI interface.

Yes, this is a low-spec machine, but it ran just fine a week ago.

I've always had wireless turned off, and I've always had Windows update turned off (Automatic Updates and BITS services shut down.) I even tried turning off the anti-virus for a while, with no success.

In task manager, processes other than Kontakt are running at 0% CPU.

With only one piano loaded in Kontakt, I have 1.1 GB RAM Available, out of the 2 GB total installed.

I'm baffled.

 

How old is the computer?

Are there any other signs of things acting differently when booting up or while running other software?

 

To answer your questions:
- The computer was new in 2007.
- It boots no differently than before.

I think I found the solution ... I uninstalled the AVG 2013 anti-virus (free version). CPU usage is lower, and I get no more click/pops/mush etc.

In my first post I noted that I had disabled AVG to see if things improved. It's control panel provides that capability. No luck. Even when disabled, the AVG background programs (of which there are five, I think) still run.

Uninstalling AVG reduced that to exactly zero AV programs. Problem solved.

So why did this happen now, whilst there were no problems a week ago? Here's my guess ...

I used to run AVG 2012. An update several weeks ago moved this computer (and five others in the house) to AVG 2013. The others are recent model desktops and laptops running Windows 7, all of them bigger and better than the piano laptop. They run fine with AVG 2013.

But so did the piano laptop! I had no problems with the piano laptop until yesterday. My guess is that there was an incremental auto-update to AVG ... and this screwed things up.

So now I have no AV on this laptop. But it's probably okay. I neither surf nor email nor IM on this computer. It's the purest computer in the house: single-purpose, piano only. I only have it on the network for file transfers and backups. So I'll be okay even without AV on this box.

 

Most likely there was some option enabled which scans each file as OS accesses it. And since Kontakt streams samples, it would scan EACH STREAMED FILE before playing it. There you get the crackles.


Anyways, a suggestion is to have absolutely no AV if you're dealing with music software. Or, if you absolutely must have an AV, forget everything except NOD32, which is the best thing out there.