External HD won't show on computer

Have a Western Digital external hard drive which I have been using for backup data and it has always shown up on "my computer" as the F drive. Using Acronis TI 9.0 as software to do this.
I have downloaded True Image 2009 and installed it-no problem. Apparently when I was trying the new TI program I did something I shouldnt have. I can not get the external HD to show up any more on my computer. Went through routine of disconnecting power cord and USB and reinstalled the drive as per instructions. No luck.
Went to "my computer, right clicked on it to bring up "Computer management ", clicked on "disk mangement" under volumes in the lower right window it shows a "disk 1 ", basic 111.79 GB, (which is the external HD) online, unallocated. My C and E drive are shown also under Volumes. The external HD does not show in Windows Explorer. Driver for the HD is updated.
Need help get my drive to show again.
Using Windows XP Home

 

Is there anything on the drive you need to salvage? If so stop now, disconnect the drive then come back for assistance.

Do you recall what exactly you did?

 

Thanks for the reply
Is there anything on the drive you need to salvage? No, it was originally a clone of my C drive using Acronis. Won't do me much good not being able to get to it
The only thing I can remember I was doing was using the new Acronis 2009 for the first time and starting to clone disk to HD when I stopped operation thinking I was doing it wrong

 

Ok, if you don't need to recover anything have you tried reformatting?

 

No I haven't tried reformating. I'm a little dense here tho. I need direction on how I can get to the disk to reformat when it doesn't show up when I open "my computer ".
Budo

 

In disk Management right click on that unallocated space and select Format (make sure you select the correct drive). After this you can change Drive letters or paths.

 

Hi Wildfire In disk Management right click on that unallocated space and select Format (make sure you select the correct drive). After this you can change Drive letters or paths
When I right click the only choices I get are:" New partition, properites or help. "
Budo

 

New Partition will do the job (one more time though WARNING you are deleting/erasing/killing/destroying the contents on that hard drive)

Selecting help won't do any harm either

 

When this is done what is the next step to get to the HD to reformat it ?
Where will it show up ?
Budo

 

Same place Budo, Disk Management. I think the name explains all.

 

Gotcha
Going to take a break for today. I want to be sure I have it all before I take this step. If I goofed I'd take the gas pipe if I formatted the wrong drive.
Will be back at tomorrow.
Thanks for all your help.
Budo

 

Success

Following the steps and great help from Wildfire I now have my external HD back and formatted and ready to use.
Thanks Wildfire for your patience in walking me thru this.
Budo

 

No problem, happy to help.