I'll give you two possible solutions.
S1: Restore the .DLL file.
- Download the WINHTTP.dll fixer here: http://www.dll-files.com/dllindex/dll-files.shtml?winhttp
- Run the program, then restart the computer after it finishes.
- Install the game.
S2: Restore your computer to an earlier setup.
- Go to Start > Accessories > System Tools > System Restore
- When the System Restore window pops up, click Choose a Different Restore Point.
- Choose a day prior to when you tried to install the game, more than 4 days is better.
- Click next and follow through, then restart your system.
- Now try installing the game again.