If you installed IE 5.5 or Internet Explorer High Encryption Pack, you can NOT install SP6/SP6a standard encryption. When you try, you receive:
You have chosen to install a version of the Service Pack with Standard Encryption onto a system with High Encryption. This is not supported. To successfully install this version of the Service Pack, you must install the High Encryption version. Press Help for more information about obtaining the High Encryption Version of this Service Pack. Service Pack Setup will now exit.
If a high encryption version of SP6 is not available:
1. use Notepad to open \I386\Update\Update.inf.
2. Locate the \[CheckSecurity.System32.files\] section.
3. Place a semicolon (;) infront of:
Schannel.dll Security.dll Ntlmssps.dll4. Save the Update.inf file.
5. Install the service pack.