Repair or Reinstall Internet Explorer6 and Outlook Express 6
Method I
One likely cause of IE6 and OE6 not functioning properly is a corrupted file. Microsoft says this is the "most" likely cause, but I think that's wishful thinking. To run a check on the files and see if one or more is corrupted use the System File Checker that is included with Windows XP.
> Click [Start] [Run] and type sfc /scannow in the [Open] box.
(Note that there is a space between sfc and /scannow)
In all likelihood you will be prompted to insert the Windows XP CD ROM. If you don't have it available there is no point in continuing unless you have the files available on your hard drive and have changed the location of the XP installation files in the registry. If you do have the files copied to the hard drive, the default install location may be modified using the registry edit shown below.
1 [Start] [Run] [Regedit]

2 Registry Key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Setup
3 Modify/Create the Value Data Type(s) and Value Name(s) as detailed below.

4 Data Type: REG_SZ (String Value) // Value Name: SourcePath

5 Setting for Value Data: [Set using the path to the installation files, i.e. G:\WXPCCP_EN]
6 Exit Registry and Reboot
Running System File Checker is not a fast process. The machine I use for the majority of my everyday work is only a P-III 866 with 784MB RAM and a 20GB/5400 RPM C drive and it took between 7-8 minutes running off the hard drive. Expect much longer times if you run from the CD. Once the System File Checker has finished, reboot and test to see if the problem has been resolved. If the problem still exists you have three choices
> In-place upgrade of Windows XP
> Repair Windows XP
> Reinstall Windows XP
Since I'm 100% against upgrade installations of XP I won't recommend that option. A repair of Windows XP may solve the problem, but the fact the problem arose in the first place makes me suspect of the current installations overall integrity. I suggest a complete reinstall of XP after backing up all data files. However, before you select any of the above choices, look at Method II below
Method II
If you are having problems only with Internet Explorer 6, proceed as follows:
[Start] [Run] [Regedit]

Registry Key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{89820200-ECBD-11cf-8B85-00AA005B4383}
Modify/Create the Value Data Type(s) and Value Name(s) as detailed below.

Data Type: DWORD // Value Name: IsInstalled

Setting for Value Data: [Change the Value from 1 to 0]

Exit Registry
If you are having problems only with Outlook Express 6, proceed as follows:
[Start] [Run] [Regedit]
Registry Key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{44BBA840-CC51-11CF-AAFA-00AA00B6015C}
Modify/Create the Value Data Type(s) and Value Name(s) as detailed below.

Data Type: DWORD // Value Name: IsInstalled

Setting for Value Data: [Change the Value from 1 to 0]

Exit Registry
If you are having problems with both Internet Explorer 6 and Outlook Express 6, proceed as follows:
Change the values in both of the registry keys as outlined above
Exit Registry
Once you have made the appropriate registry changes use the link below to download and install Internet Explorer 6. The Internet Explorer 6 download includes Outlook Express 6. Reboot and test for proper operation

- srikanth dhanwada