My 2nd SATA HDD suffers big slowdowns

First of all, I have the following setup:

Pentium 4 (2.93Ghz)
2 GB Ram
ATI Radeon X300
Windows XP SP2 Pro
1 HDD SATA 160 GB (with windows on it)
1 HDD SATA 320 GB (this is the problematic HDD)
2 HDD extern USB 2.0

I have a big problem with my 2nd SATA harddisk. Everytime I restart my computer, the HDD has to be verified in three steps (CHDSK or something like that), I let it finish almost 4 times now, but it always wants to verify the integrity of the disk again on a new restart.
During the scan he finds errors in the index but seems to correct them...
But the problem is, the Harddisk is extremely slow... Copying files from this disk to one of my external HDDs takes ages (200kbps)
I'm now trying to backup all files on it to format the HDD... But those are about 150 GB, it will take ages to copy them to another HDD.
Is there any solution? Is my HDD broken?
Thanks in advance

1 HDD SATA 320 GB
Sounds faulty to me

Yes do a full backup (even to DVD's or Flash Drives (to avoid filling up your other drives)

You can try a full format, but I believe this harddrive is faulty
You can do a HardDrive manufacture test (download utility) to fully confirm

where do i get this harddrive manufacture test? faulty means what exactly? broken?
thanks

If it's a Wetern Digital harddrive got to Western Digital website (and so forth)

Faulty HardDrive usually means it is about to fail (or Stop completely)

by the way, the harddrive is a 320 GB SATA 2 CAVIAR 8 MB

http://support.wdc.com/download/?cxml=n&pid=999&swid=3