Which internal hard drive will work with my laptop? I need to buy a upgrade on ebay.?

I have a Sony Vaio NV170 laptop (it also says PCG-NV170 on it), 30GB hard drive, 256MB ram, i litterally erased everything off it except to be able to get online, i have windows xp home, and just IE 7 and Avast antivirus and Spybot and thats it, and its so slow and freezes up, i have done all the updates and i have high speed satelite. i need a new internal hard drive. Which brand/model will work for my computer? if you dont know, where can i find out ? (without going to the computer store and paying $$$ just to find out)

Which internal hard drive will work with my laptop? I need to buy a upgrade on ebay.?photoshop

You mean like this one?

http://cgi.ebay.com/160GB-Hard-Drive-for...

(Use your Ebay skills of course. I don't know this seller. Does have over 26000 sales and has a 100% satisfaction feedback. Myself, I would contact him, and ask if this drive will work, what the DOA return is,(Dead On Arrival. Once in a great while this happens. Doesn't look like it's happened to this seller however! lol! 100% rating! Why do I think it'll work? Scroll down the page. Under Compatibility, see the heading PCB with the various versions to the right? NV is listed. Your NV170 is a series of NV's. They all use this style of harddrive)

Edit: Yes it needs more space. Once your harddrive reaches 50% capacity it starts to slow down. Where you're at it should be crawling. I would suggest also, to burn off your personal stuff out of your My Documents folder to disk/s. Then do a System Restore, and go back as far as you can. You'll lose any downloaded programs, and applications however, that have been downloaded after the restore date you choose. (Tip: When you get into System Restore, and get to the screen where it shows the calendar, click right on the calendar date. It doesn't tell you that, just says "Pick a date to restore to".)