Yeah, you're actually running at 44.1 kHz on your home system without you knowing it. You indicated you are utilizing a Sony PC. It would default to clocking at 44.1 kHz if you have played CDs or downloaded MP3's.

Go to control panels. Under the audio section, you may find your interface properties. It's there you may be able to change your sample rate to 48 kHz. It's also possible that the onboard computer sound device is dictating the clock. Perhaps because you have played a CD? And all CDs are at 44.1 kHz. What was the reason for creating the original project at 48 kHz? Wasn't designed for video? That's the default sample rate for video. And the mathematics do not transcode down to 44.1 kHz and a proper mathematical way. So there is really no reason to create 48 kHz projects unless they are for video purposes and not CD, audio purposes. It doesn't matter if you can hear a difference between 44.1 kHz & 48 kHz. Though it is possible and done frequently to transcode down to 44.1 kHz there is just no reason on this little planet to recorded 48 kHz for strictly audio releases. 24-bit maybe over 16 bit but even then, 16 bit is quite adequate and proper recording levels are taken into account. 24-bit dictates working dynamic range. 24-bit allows for a 140 DB dynamic range. The joke on most people is that all of your audio equipment and even within your interface can rarely exceed 100-110 DB of actual dynamic range. The 140 DB capability of 24-bit comes into play when you are processing effects. But even then, that's for people that do not know how to properly adjust audio levels, digitally to keep overloads of the waveform from happening. I've been recording digitally since 1983 where we only had 16 bit converters. And 16 bit converters allow for a 96 DB dynamic range. Which is way more than we ever had with analog tape recording. So I still work within 16 bits. It's 100% adequate. Provided you know what you're doing. And then even processing can work more efficiently and faster. It presents less of a load to the CPU. And that allows for more processing on slightly older computers than is possible with 24-bit projects. It's not quite the same as it was in our childhood when connecting the dots to create a picture. In fact I personally see very little reason to utilize 24-bit. But maybe that's because I know what I'm doing? To me, 24-bit is for beginners. It's like a child who has not yet learned how to utilize a fork, spoon & knife to feed themselves with. Other people can argue this concept but let's face it, what 24-bit MP3's have you downloaded? Resolution does not come from the bit depth but from the sample rate. 88.2 kHz & 96 kHz at 16 bit is higher in resolution than 24-bit at 44.1 kHz/48 kHz. This is a concept most people can't seem to grasp. Most current digital multi-track standalone recorders all run of 24-bit. Though you frequently have an option to run at 16 bit. But most folks don't bother. And that's also because our current disk drive technology offers up huge storage on the disk drives. 16 bit requires a lot less storage space. I know this is not the question you have asked but I thought it was important for you to know.

We're not working with analog tape anymore.
Mx. Remy Ann David

Thanks for the reply, yes I have a sony viao PC running win7 and there was a place in my control panel where it was set to 44.1 but I changed it to 48 and restarted my computer booted up pro tools and it's still slow. please help

You might need to go into your bios and disable Sony's onboard sound device. Then try again.

That's my second thought?
Mx. Remy Ann David

What is your PT8 interface? The ASIO driver for THAT device needs to be set for 48k. The Win7 onboard settings are irrelevant.