If your using Zone Alarm ( or possibly another firewall) check the settings
.... you can also try reregistering the following files
Verify that the Microsoft Cryptographic Services Service Is Started
To verify that the Cryptographic Services service is started (and to start
it if it is not):
1. Click Start, and then click Run.
2. In the Open box, type cmd, and then click OK.
3. At the command prompt, type net start cryptsvc, and then press ENTER.
4. Type exit to quit Command Prompt.
Register .Dll Files
Re-register the following .dll files:
Softpub.dll
Wintrust.dll
Initpki.dll
Dssenh.dll
Rsaenh.dll
Gpkcsp.dll
Sccbase.dll
Slbcsp.dll
Cryptdlg.dll
To do so:
1. Click Start, and then click Run.
2. In the Open box, type cmd, and then click OK.
3. At the command prompt, type the following lines and press ENTER after
each line:
regsvr32 softpub.dll
regsvr32 wintrust.dll
regsvr32 initpki.dll
regsvr32 dssenh.dll
regsvr32 rsaenh.dll
regsvr32 gpkcsp.dll
regsvr32 sccbase.dll
regsvr32 slbcsp.dll
regsvr32 cryptdlg.dll
4. Click OK when you receive the message that DllRegisterServer in FileName
succeeded.
5. Type exit to quit Command Prompt.