Re-registering all components of Internet Explorer will take considerable time and effort - plus there are chances that you may miss out on any component. I will suggest creating a batch file so that all of them are re-registered with one command.
To create a batch file, open Notepad. Copy the commands given below to the file. Click Save. In the Save As Dialog box, Select All File Types. In the file name field, type in "C:\reregister.bat" and press Enter. The commands to be copied to the Notepad file before saving it are:
regsvr32 /u /s urlmon.dll
regsvr32 /u /s mshtml.dll
regsvr32 /u /s shdocvw.dll
regsvr32 /u /s browseui.dll
regsvr32 /u /s jscript.dll
regsvr32 /u /s vbscript.dll
regsvr32 /u /s scrrun.dll
regsvr32 /u /s msxml.dll
regsvr32 /u /s actxprxy.dll
regsvr32 /u /s softpub.dll
regsvr32 /u /s wintrust.dll
regsvr32 /u /s dssenh.dll
regsvr32 /u /s rsaenh.dll
regsvr32 /u /s gpkcsp.dll
regsvr32 /u /s sccbase.dll
regsvr32 /u /s slbcsp.dll
regsvr32 /u /s cryptdlg.dll
regsvr32 /u /s oleaut32.dll
regsvr32 /u /s ole32.dll
regsvr32 /u /s shell32.dll
regsvr32 /u /s initpki.dll
regsvr32 /u /s msjava.dll
regsvr32 /s urlmon.dll
regsvr32 /s mshtml.dll
regsvr32 /s shdocvw.dll
regsvr32 /s browseui.dll
regsvr32 /s jscript.dll
regsvr32 /s vbscript.dll
regsvr32 /s scrrun.dll
regsvr32 /s msxml.dll
regsvr32 /s actxprxy.dll
regsvr32 /s softpub.dll
regsvr32 /s wintrust.dll
regsvr32 /s dssenh.dll
regsvr32 /s rsaenh.dll
regsvr32 /s gpkcsp.dll
regsvr32 /s sccbase.dll
regsvr32 /s slbcsp.dll
regsvr32 /s cryptdlg.dll
regsvr32 /s oleaut32.dll
regsvr32 /s ole32.dll
regsvr32 /s shell32.dll
regsvr32 /s initpki.dll
regsvr32 /s msjava.dll
Once you have saved the file, it is time to run the file so that all components are re-registered. Before running the command, close all Windows Explorer and Windows Internet Explorer Windows. Open Start Menu and select Run. In the Run dialog box, type "C:\reregister.bat" without quotes.
You can see the execution of each command in a black window. Once the process is finished (you will know when the black window is closed), you need to restart the computer. After restarting the computer, open Internet Explorer and work on it for a while. If it does not create any problem, you have successfully fixed the issue where Internet Explorer 7 shuts down.
In case the problem still persists, you will have to reinstall Windows Internet Explorer 7 to see if it helps. If you are using Vista, please read our article, How to reinstall IE in Vista and Windows 7. If reinstallation solves the problem, you are good to go, else you will have to contact Microsoft Technical Support and inform them that Internet Explorer 7 shuts down frequently so that they assist you in fixing the problem.
My Opinion: Upgrade to Internet Explorer 8. It offers more stability while also giving higher security among many other features. This way, you won't have to lose your work when Windows Internet Explorer 7 shuts down while you are working.