There are two issues that you will find out when you finish the installation of SQL Server 2012 or SQL Server 2008 R2:

1. When you try to access Reporting Services using your IE browser, it will constantly prompt you to enter username and password.
2. After the successful entry of login details in IE, you will get the following error message:

User ‘Domain\User’ does not have required permissions. Verify that sufficient permissions have been granted and Windows User Account Control (UAC) restrictions have been addressed.

To resolve the first issue, please read the following article:

SSRS Prompt username and password

Here is the steps that you need to do to resolve the second issue:

1. From Start > All Programs > Internet Explorer, Right Click and choose Run as administrator

2, Enter the Reporting Services URL: http://localhost/Reports_SQLExpress

3. Running as administrator will allow you to have access to Site Settings. Click on it:

4. You will see the General Site Settings page:

5. Click on Security from the left side menu and choose New Role Assignment:

6. Add the username or Group that you want to grant permission to and select the appropriate role:

7. Now go to Home page and click on Folder Settings. Add the username or Group that you want to grant permission to the main Home page:

8. All done now. You can normally open IE and it will work without an AUC error. You can also create Folders within the Home page and restrict access to specific users.

After the successful installation of SQL Sever Reporting Services 2012 or 2008 R2 (read this article for an installation tutorial: SQL Server 2012 Express Installation Tutorial), you will get constantly prompted with Windows Security dialog box to enter login details. This is related to IE9 which ships with Windows 7 operating systems.

It is easy to fix this issue by following these steps:

1. Open Internet Explorer (IE9) and from the tools menu, choose Internet Options:

2. From the Security Tab, choose Local intranet and click on Sites:

3. Click on Advanced button:

4. Type in localhost in Add this website text field and click on Add button (Un-tick the box Require server verification (https:) for all sites in this zone):

All done. If you open your IE again and type in Reporting Services URL, you will no longer be prompted to enter login details.

However, you may see a UAC (User Access Control) authorization error message. To learn how to resolve this issue, read this article:

SQL Server 2012 UAC authorization error