Windows 7 - create default user profile

1. Make a backup first: Copy C:\Users\Default to C:\Users\Default.original
2. Create a new user "custom_user" (in local Administrators group).
3. Customize the profile as you wish.
4. Logoff custom_user.
5. Login as Administrator.
6. Remove "custom_user" from Administrators group
7. Open regedit. go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList.
8. Change Default to point to %SystemDrive%\Users\custom_user (instead of %SystemDrive%\Users\Default).
9. Logoff and relogin as Administrator again.
10. Go to Control Panel & select System. Select Advanced System Setting
11. Select Advanced tab.  Under User Profiles select the Settings button. 
12. Select the Default Profile (which you pointed to custom_user in the registry) & select Copy to. Browse to c:\Users\Default & click OK.
13. Under Permitted to use, click Change
14. Give permissions to Everyone. Finally click OK.  (The contents of custom_default with be copied over default (the original default).
15. After it gets done, go back to regedit & change the back to %SystemDrive%\Users\Default.
16. Regedit
1. Load Hive
2. Change the access right of Hive to "Everyone"
3. Search any username
4. Search c:\users\custom_user
5. Replace SID with .DEFAULT

Reference:

1. http://itknowledgeexchange.techtarget.com/itanswers/default-user-custom-profile-in-windows-7-without-sysprep/
2. http://stealthpuppy.com/customize-the-windows-default-profile/
3. https://cwiki.apache.org/confluence/display/VCL/How+to+Configure+the+Windows+Default+User+Profile
4. http://www.sevenforums.com/customization/238276-heres-how-create-default-profile-without-using-sysprep.html
5. https://www.blogger.com/blogger.g?blogID=7792823508351042656#editor/target=post;postID=4307277176325625829;onPublishedMenu=allposts;onClosedMenu=allposts;postNum=0;src=link
6. http://noltechinc.com/user-management/modifying-the-default-user-profile-in-windows-7