Windows 7 - Hard Drive Issues?

Hello, I am currently worried of my hard drives. I have 2 of them, one is a Western Digital Caviar Blue, about 2 years old I think. The second is a Western Digital as well, but I'm unsure of the type and age, it's a 150GB drive.
One of these drives are making an odd noise, I suspect it's the main drive, the 500GB Caviar Blue. Reason being is because after starting up my system and selecting either Windows 7 or Windows XP it does a Disk Check before going to the Welcome screen, it does not do the Disk Check every time, but it happens quite often. Disk Check of course displays no issues upon completing. The thing I notice that happens, but not very often, it's about a 1 second kind of low screech noise coming from my computer tower. It is making me worried of my computer health and how much longer is might live.

Update: Could the screech like noise possibly be the plastic fan on my CPU? It causes slight vibration.

Hello.

I would suggest checking the SMART data of your drives. To do so, you can download SpeedFan. Once installed, run as admin then go to the SMART tab and select your drives. You can see the "Performance" and "Fitness" bars. If they are dramatically low, I would suggest cbuying an hard drive as fast as possible to save your data.

Backup all your data now, and then run Seagate Seatools to verify the SMART attributes. It will work with WD drives.

Speedfan reports that both drives are in very good condition, anything else, any other ideas of what is happening?

EDIT: Downloading Seatools at the moment.

The drive size sounds a bit odd for sure since WD drives come in 160gb models. The best thing for WD drives however when unsure is to download and run their LifeGuard diagnostics utility. WD Support / Downloads / SATA & SAS / WD Caviar Blue / SE / SE16 (SATA II)

That page is for the 500gb Blue model. For older Caviar and Caviar SE models they fall under Legacy Internal. WD Support / Downloads / Legacy Internal / WD Caviar SE / SE16 (SATA I)

As far as fans screeching when first powering up a system that depends on the fans themselves. Typically that's where the largest draw on power is seen at post time as well as getting those fans turning! Some fan on 3rd party not stock sink will tend to scream a little at startup or even when putting a good load on the cpu.

Seagate Seatools ran the SMART test and both drives passed.

@Night Hawk: They are PATA hard drives, not SATA.

Your drives are safe... for now. Methinks that backing up would be a nice idea just in case something happens.

Then you would need to go to the main support page seen at WD Support / Downloads / Select Product

Once you select the correct photo for the model series you have the next page is seen at WD Support / Downloads / EIDE (PATA)

Since they no longer list Caviar SE as one of their model series presently available you can enter the model number seen on the post screen when first powering up. What you see there now unfortunately is mainly for their latest updated versions for the newer model lineup.

With the drives having passed other tests your next step would be scheduling a checkdisk tool manually with the repair switches added at the end. Simply open up a command prompt and type in "chkdsk /r /f" for the tool to look for and repair any errors.

The automatic start being seen at times is without the repair switches added simply left scanning the drives. That wasn't helping you any. At least the drives seem to in good shape however.