Login pop-up in SharePoint

If you gets login pop-up whenever you opens any SharePoint page in Internet Explorer (IE), then solve this issue we need to change following IE settings...

Add the SharePoint site to the list of Local Intranet (IE7/8).
Steps:

1) In Internet Explorer, on the Tools menu, click Internet Options. 
2) On the Security tab, in the Select a Web content zone to specify its security settings box, click Local Intranet, and then click Sites. 
3) Clear the Require server verification (https:) for all sites in this zone check box. 
4) In the Add this Web site to the zone box, type the URL to your site, and then click Add. 
5) Click Close to close the Local Intranet dialog box. 
6) Click OK to close the Internet Options dialog box. 

Reference--
MSDN Forum