When I'm going to the link http://localhost:1080/splash2.html and clicking on Web Shell Client( shell-in-a-box), then it's restricting me from visiting the login page. A page is getting open saying something about Oracle 10g , may be I'm facing this problem because i got Oracle 10 installed on my laptop, I'm not sure. Please suggest some solution, I'll be very thankful :-)
As you mentioned that while accessing the splash screen page you are seeing Oracle Software home page then your issue might be similar to the one described here:
May be you are running Oracle 10g database on your localhost. Oracle 10g DB also uses port 8080 as default port. So either change the Oracle Web port from 8080 to something else or stop it while accessing sandbox.
The other option may be to change the Sandbox Prot mappings rules.