There are many problems regarding downgrading internet explorer. One of these problems is some do not have permission to downgrade it. Remember that you cannot downgrade it but you can replace the one that you have.
Here's how:

1. If you want to downgrade your internet explorer you have to remove your internet explorer 7 first.

2. Click start, then select and click control panel.

3. A new window will open, this is called the control panel window. Look for add.remove programs and double click it.

4. Once the programs appeared, you can either delete it or change it.

5. If you see the internet explorer in there point the mouse in that file, two button will appear at the right side of the file description. These two buttons is the delete or change button.

6. You can now delete IE 7. Once IE7 is deleted you can now download and install internet explorer 6.

Congratulation.