Some of you might Google before you find out that Microsoft made a tutorial on how to customize a Windows 7 themes. For that purpose I will post that tutorial for your information.
You can change individual parts themes (the pictures, colors, and sounds), and then save the revised themes for your own use or to share with other people.
To change parts of a theme
Open Personalization by clicking the Start button , and then clicking Control Panel. In the search box, type personalization, and then click Personalization.
Click the theme that you want to change to apply it to your desktop.
Do one or more of the following:
To change the background, click Desktop Background, select the check box for the image that you want to use, and then click Save changes.
To change the color of window borders, click Window Color, click the color that you want to use, adjust the intensity, and then click Save changes.
To change the sounds for the theme, click Sounds, click an item in the Sound Schemes list, and then click OK.
To add or change a screen saver, click Screen Saver, click an item in the Screen saver list, change any settings that you want to change, and then click OK.
Your revised theme will appear under My Themes as an unsaved theme.
To save your revised theme to use on your computer, follow these steps:
Open Personalization by clicking the Start button , and then clicking Control Panel. In the search box, type personalization, and then click Personalization.
Click your revised theme to apply it to the desktop.
Click Save theme.
Type a name for your theme, and then click Save.
The theme will appear under My Themes. Note that themes saved this way can’t be shared with other people.
To save a revised theme to share with friends and family.
To share a revised theme, follow the steps below. You can share your theme using e‑mail, a network, or an external hard disk.
Open Personalization by clicking the Start button , and then clicking Control Panel. In the search box, type personalization, and then click Personalization.
Click your revised theme to apply it to the desktop.
Right-click the theme, and then click Save theme for sharing.
In the File name box, type a name for your theme, and then click Save.
By default, Windows saves the theme in your My Documents folder.