Tiger randomly stopped allowing my External Hard drive to mount and...

Question

Hello, I have been using an External Hard Drive (1 terabyte Seagate, new) for a couple months if not a year by now for saving movies, and all of my iTunes on it. Its been working wonderfully. However it recently stopped being able to mount citing invalid hard drive and gives me the options of either eject, ignore, or initialize. Im not sure what to do. And also my computer has been acting funny every since the day it started. I will walk you through it step by step.
July 6th I was surfing the web and unfortunetly clicked on a link that aparently contained a trojan. Or atleast thats what my Antivirus notified me of. I had downloaded the trojan some how without a pop up or anything telling me I was downloading anything. (using safari) So i ran a virus scan and saw one virus was in my system and that it couldnt be deleted or repaired by my antivirus program, Im working on getting rid of that but at the time I had my Seagate 1 terabyte external hard drive attached via fire wire to my Macbook. It was working then.
Later that day I unplugged my hard drive and took my laptop around a little bit, nothing unusual. Then when i came back later that night I tried plugging in my hard drive and a pop up stated that the hard drive was unable to mount and I could either eject, ignore, or initilize. I tried may different routes, restarting, letting it all rest, etc. And in Disk Utility i try to verify the disc and it says its unable to and needs repairs. So I try repairing the disc and it says unable to due to an error.
Then yesterday I went to my applications and noticed none of my applications are there anymore. These applications were saved on the internal hard drive so it was very odd to me. However i can still use spotlight to find and open my apps.
My question is, What can I do to allow my external hard drive to mount? I dont figure it is the trojan on my system but could it be? If so how would I fix it? Im mostly worried about getting the data off the external hard drive then I can reformat it. Or if theres a way to just get it back to normal without reformatting Id love to hear it. As for the applications missing and the trojan on my internal hard drive I can fix that, at the very least Ill just reboot my system with my original OS Disc and just start fresh, its about time anyways.
But please. If anyone has ever had their external hard drive just stop mounting and figured out what to do I would be ever so grateful to hear how you did so. The hard drive itself isnt damaged, its not making any unusual sounds. Whenever i plug it into the computer it acts like normal (turning on and what not) until the computer tells me it cannot mount then nothing happens. Ive looked online and it seems to be a software issue.
If its any help I was downloading a torrent (.avi, no viruses) at the time. I know sometimes if one file on the hard drive becomes corrupt the whole thing becomes unusable. Regardless I would appreciate it if anyone knows a way to at the very least retreive the files on the drive, but preferably know how to just get it back to normal. If i could get it to force mount (via terminal or something) I know which file would possibly be the corrupt one or something so I could work with it.

Answer 1

Bejan:
Thanks for posting back with the pics of the messages from your computer. Disk Utility reports "Underlying task reported failure" when repairing a volume is a directory error which cannot be repaired by Disk Utility. Unfortunately, Disk Warrior may not be able to replace the rebuilt directory, either. Tech Tool Pro has a better chance of repairing it, although this particular directory issue can be stubborn, and is often rooted in a hardware issue. Your surest bet is to backup/clone the information on the HDD using a utility like SuperDuper or Carbon Copy Cloner, completely reformat and erase the HDD (directions below), then restore data from backup.
Formatting, Partitioning Erasing an External HDD
• Connect external HDD to computer
• Turn on external HDD
• Start up computer and log in
• Go to Applications > Utilities > Disk Utility and launch DU.
• Select your HDD (manufacturer ID) in left side bar.
• Select Partition tab in main panel.
• Click on Options button
• Select Apple Partition Map (PPC Macs) or GUID Partition Table (Intel Macs)
• Click OK
• Select number of partitions in pull-down menu above Volume diagram.
For more partitions than one, after you have selected the number of partitions adjust the size of the partition by selecting the top partition and typing in the size; then move down if more adjustments need to be made.
(See Dr. Smoke’s FAQ Backup and Recovery for tips on partitioning external HDD)
• Type in name in Name field (usually Macintosh HD)
• Select Volume Format as Mac OS Extended (Journaled)
• Click Partition button at bottom of panel.
• Select Erase tab
• Select the sub-volume (indented) under Manufacturer ID
• Check to be sure your Volume Name and Volume Format are correct.
• Click Erase button
• Repeat above procedure to erase each partition
• Quit Disk Utility.
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