Use FREE & FREEWARE software
NotepadTabs: Open Multiple text files in different tabs
Notepad Tabs is a freeware software to use multiple text files in different tabs same IE7 or Firefox. It is a alternative software of Microsoft Notepad. You can open and use multiple text files and switch to different file by clicking respective tab or shortcut. For interface you can use several themes.
It works with Windows 7, Vista and XP but need the .NET Framework 2.0 or later versions.
Download Link: http://www.notepadtabs.com/download.aspx