MBR error

[iviv]

Right, can't be bothered to add fluff to this.

A friend just sent me a file over MSN, and NOD32 opened and scanned it as usual, no viruses. However, in the pre-scan checks it did, it flagged up:

Error occurred while scanning MBR sector of the 3. physical disk. Error reading sector.

Now, I'm guessing the MBR is the Master Boot Record. I've not had this error before, and haven't been doing anything strange to my system, so don't know whats caused it. However, I'm now very reluctant to restart my laptop, since if there's a problem with the MBR, it could prevent me booting up? And I don't have an XP install disk here to do a repair if needed (Though a flatmate may have one).
So, is there something I can do to confirm the error exists, and get rid of it without rebooting?

 

[Wiggins]

You may have a bad sector on the MBR. The only thing you could do is a 'fixmbr' with an XP Disk although if your laptop came pre-installed with XP, it may have a recovery console hidden on a partition.

Edit: You may find this will be moved to Windows & other Software.

 

[iviv]

Its a Dell, so no recovery partition. The CDs are all in my loft at home, 4 hours away.
Is there any program I can use to confirm there is an error?
I've tried the right click c: > tools > Error checking, but the checks don't get very far since windows is using the files >_> Still, I've unchecked both boxes, and its nearing the end of phase 2, whatever that means.

I'm scared to restart >_>

 

[iviv]

Right, just had the idea to remove the external hard drive and my ipod, and NOD isn't flagging up any errors now. I guess it was looking for some sort of boot record on one of them, for whatever reason >_>