5400 RPM Hard Drive

As long as you have a 7200RPM hard drive for your audio, you will be alright. That's amazing that it came with such a drive in it though...II thought you where talking about a laptop, but its a desktop and there usually come with 7200rpm drives.
You could just take the 5200 rpm drive out and replace it, if problems occur, but as long as your audio driver is 7200RPM, you should be fine.

If your really unhappy, see if you can return the pc?
Cj

I'm truly suprised that a notebook hard drive should be in a desktop machine - have a chat with your supplier and see if a swap + a few $ is possible.  They will probably say no - due to warrantee etc: but you never know.

The other option is to buy and install a small SATA hard drive and load your Windows and Programs on that - make this your C: drive. 

Then use the TB hard drive for all your files and folders/archive - (D: usually reserved for optical) - first available after that is usually E,: F:, drive.  Card reader may hog the, but just go for last letter available.

Try to pick the fastest drive you can afford. You only need enough space on it to hold the OS + Programs/Applications/VST's/loops/samples, and believe me 80GB is more than enough.

Even though the 5,200 is slower, once the OS and Programs are loaded and running from the fast drive, the read/write- send/fetch to and from the slower drive is not that important.  Make sure that 'system performance is set to applications, and make your paging file about 2x your RAM size. Don't move the paging file away from the fast drive.

If you know a bit about the "Tree - Branches" of files and folders, it may be best to move some of your program presets destinations to the slower drive, eg; final destination of projects/completed works/final mix/music and doc archive etc: all pointing the 'save' to the TB drive.
 
Go through all your programs 'options' or 'global' dialogues and point the larger "saves" to the TB drive

Hope this helps - Kevin

They're throwing slower hard drives into machines now to save some money. A 5400 RPM drive is not necessarily a laptop hard drive; it may be a full-size drive running at a slower speed.

Ultimately, you'll want the biggest, fastest drives you can afford. You probably can't return this machine without a "restocking fee", so you might just want to accept the fact that you saved some money on it, and spend another $120 on two good SATA-II drives--one for your instruments, and a larger one for your recordings (keep Windows 7 on the drive that came with the PC). Newegg.com and other on-line retailers have great deals on them--just check the RPM speed before you buy!

A few words of advice: Stay away from Seagate for anything over 500 GB, and don't get Western Digital "Green" series drives. They're reliable, but slow.