Follow these steps:
1. Uninstall IE7.
Step 1: Make hidden files and hidden folders visible
a. Click Start, and then click My Documents.
b. On the Tools menu, click Folder Options.
c. Click the View tab.
d. In the Advanced settings list, under Hidden files and folders, click Show hidden files and folders, and then click OK.
Step 2: Run Spuninst.exe to uninstall Internet Explorer 7
a. Click Start, and then click Run.
b. In the Open box, type %windir%\ie7\spuninst\spuninst.exe , and then click OK.
c. Follow the wizard instructions to uninstall Internet Explorer 7.
2. After IE7 is uninstalled restart the PC and check that IE6 is back.
After IE6 is back then Reregister the following IE6 DLLs. (Copy and paste these files in a notepad, save it as .bat and run the batch file)
regsvr32 urlmon.dll then enter.
regsvr32 mshtml.dll then enter.
regsvr32 shdocvw.dll then enter.
regsvr32 browseui.dll then enter.
regsvr32 msjava.dll then enter.
regsvr32 jscript.dll then enter.
regsvr32 vbscript.dll then enter.
regsvr32 scrrun.dll then enter.
regsvr32 msxml.dll then enter.
regsvr32 actxprxy.dll then enter
regsvr32 shell32.dll then enter
regsvr32 softpub.dll then enter.
regsvr32 wintrust.dll then enter.
regsvr32 dssenh.dll then enter.
regsvr32 rsaenh.dll then enter.
regsvr32 gpkcsp.dll then enter.
regsvr32 sccbase.dll then enter.
regsvr32 slbcsp.dll then enter.
regsvr32 cryptdlg.dll then enter.
regsvr32 Oleaut32.dll then enter
regsvr32 initpki.dll then enter. This will take a little bit of time to register
regsvr32 softpub.dll then enter.
regsvr32 wintrust.dll then enter.
regsvr32 dssenh.dll then enter.
regsvr32 rsaenh.dll then enter.
regsvr32 gpkcsp.dll then enter.
regsvr32 sccbase.dll then enter.
regsvr32 slbcsp.dll then enter.
regsvr32 cryptdlg.dll then enter.
regsvr32 initpki.dll then enter. This one takes longer to register.
- Type REGSVR32.EXE SOFTPUB.DLL
- Type REGSVR32.EXE WINTRUST.DLL
- Type REGSVR32.EXE INITPKI.DLL
- Type REGSVR32.EXE DSSENH.DLL
- Type REGSVR32.EXE RSAENH.DLL
- Type REGSVR32.EXE GPKCSP.DLL
3. Repair IE from ie.inf file (Start - run - inf) Right click on the IE.inf file and click on Install. It will ask for the XP CD and will repair in just two minutes.
4. Now try to install your McAfee.