Well, Cyclic Redundancy Check is a "CRC" error, it's just being spelled out for you.  That means the checksum failed.  CRD is an error correction code that is recorded in each sector of a disk and used to catch errors in the data itself.  This is used to detect RANDOM (or accidental) changes in data, and not deliberate ones.  A CRC failure means the data was altered by an error, be it physical damage to the sector (absence of data), or power surges; rather than you making the change.

The request could not be performed because of an I/O device error:  This happens for ALL kinds of reasons. I got a brand new 320GB drive, and while using U-torrent, I keep getting this error on a certain torrent, when there is nothing wrong with the drive, so I don't know why I get that error.  I restart the torrent, it's fine for about 5 minutes, then I get it again, so THAT is strange.  However, it is generally a hardware failure in the drive itself (take your pick), or any point in the logic circuits from the PC to the drive.  It does also happen like if the drive power or voltage would fail during a write, or a bad spot found on the HDD during a write, but it is generally a hardware failure.

I replace my hard disks every THREE years, whether they need it or not.  Unless I find a deal on one sooner, and it is a lager drive, I buy it.   I got a 160GB last year, then got the 320 this year, it was CHEAPER than the 160 I bought last year; I had the money, so I got it.   I replace my hard disks frequently enough, that the average person would think it's stupid...

Usually, I go the warranty time then replace it.  Seagate has a 5-year warranty on their drives, but they don't protect DATA, just the hardware.  Most others are 3-years.  So, yeah, you can get the drive replaced, but the data is gone, and who in our reasons for use, wants to pay hundreds to over a thousand dollars for data recovery?  Not me...  I back up all my DATA, not applications.  The apps can be reinstalled, the data cannot.

Everything on my HDD can either be re downloaded or reinstalled. Theres nothing of importance that ill loose besides my time and bandwidth.

I turned off my external hdd. Theres a switch on it. And now everything run smoother. Before i was getting all kinds of crashes and what not. Could my external hdd me infected with virus's or just that messed up?

That HDD is doing you a favor not letting you copy Linkin Park.....

lol ya you did

I misread what you posted again so my bad. You could have a virus on your external HDD affecting your OS. Have you tried running a virus scan on it?