If you have IE 5.0 or above you may have to configure the security setting of IE in order to purchase from most web stores.
To configure IE security settings do these steps:
1) From the IE menu select Tools | Internet Options.
2) On the Internet Options dialog select the Security tab.
CONFIGURATION 1:
3) Select the Internet zone by clicking on the Internet icon (it will probably be selected by default).
4) The security for that level is probably set to High. Adjust the security setting to Medium.
If lowering the security setting to Medium is not acceptable try Configuration 2 and 3.
CONFIGURATION 2:
3) Select the Internet zone by clicking on the Internet icon (it will probably be selected by default).
4) Click the Custom Level button. The Security Settings dialog will appear.
5) Scroll down the settings until you find "Allow per session cookies (not stored)".
6) Select Enable.
CONFIGURATION 3:
7) On the Internet Options dialog select the Privacy tab.
8) Move the slider to select "medium".
9) Click OK and the dialog box. will close
You should now be able to complete your purchase.