Hi, My new Windows 7 computer has been made unbootable because I tried to change a drive letter. What can I solve this problem ? How can I prevent the same thing happen again? I will explain what happened. Yesterday, I booted my Windows 7 computer and as it was booting I plugged in my camcorder in a spare USB port. When it booted, I saw that the letter of my external hard drive had changed from I to J. I could not have this for then the Search documents function would not work. So I opened up Disk Management and tried to change the drive letter from J to I but the letter I was not available. I had used Disk management before and I knew that the drive letter I must have been used by some obscure drive in my computer. I decided to change the F drive to R in an attempt to make the letter I available. I then tried to change the letter drive from J to I and this time the drive letter I was available. I changed the drive letter but I did not restart my computer immediately. Later I shut down the computer. But when I tried to boot up my computer again, it would not boot at all. I changed the plug fuse 3 times and the same thing happened so I know it was not plug fuse. I have all my data and my Acronis backup in my external hard drive. What am I going to do? Please help.