On the Add New Entry tab, click on the Linux/BSD tab in the Operating Systems section. Knowing that Mint 10 (and Ubuntu 10.10) uses GRUB 2, not GRUB Legacy, Select GRUB 2 from the dropdown menu.
This just shows the window with the correct option selected. Click once on the Add Entry button, then on the View Settings button to view the entries in the new boot menu.
This shows the boot menu with the Linux entry just added. The Windows 7 entry is the default. If you want to modify the boot order and rename the Linux label, click on the Edit Boot Menu button.
This is the default boot order. To make the Linux entry the default, select it and click on the Up button. To change the label from NeoSmart Linux to Linux Mint 10 (or Ubuntu 10.10), select it and click on the Rename button.
This is the final result. Click on Save Settings, reboot the computer and you will see a Windows 7 boot menu similar to the one here.
Hope this has helped. If you need help with a configuration different from the one presented here, join Mint forum or Ubuntu forum, ask your question and I will do my best to get you the appropriate answer. You can have quality articles like this delivered automatically to your feed reader or inbox by subscribing via RSS or email.