If you want to change your hard drives letter or your cd-rom drive letter, this is the tip you want.
1. Click the start button
2. Go into Administrative tools (either in the start button or in "All Programs"
3. From Administrative Tools, go into "Computer Management"
4. In "Computer Management", click on "Disk Management" under "Storage" from the left menu
5. You should see a window from the lower right hand corner open (it shows all the hard disk drives and cd-rom drives)
6. To change...
...hard drive, click on the hard disk with a blue horizonal bar, the box should be shaded; next right click that box that you desire to change the letter then click on "Change Letter Drive and Path"
...cd-rom drive, click on the box that you desire the drive letter; next right click that box that you desire to change the letter then click on "Change Letter Drive and Path"
7. click the "change..." button
8. from the "assign the following drive letter", select the letter you want to assign to the hard drive or the cd-rom drive
9. click ok
10. click ok
11. (optional) redo the whole step to reassign other hard drives or cd-rom drives
There! You have succeeded in changing the hard drive or cd-rom drive letter. Enjoy!
Notes: You can not change the drive letter of your boot or system drive this way. You can not assign drive letters that are already in use. Assign temporary letters as a workaround.