I had the same problem:
1. go to your start-menu and select "run" (or something similar if your windows is not in english)
2. write "regedit" (without the quotes) and press "ok" or enter
3. select HKEY_LOCAL_MACHINE -> SOFTWARE
4. if there is not a folder called "Paradox Interactive", create it by right-clicking on SOFTWARE and selecting "new" -> "key". Name it Paradox Interactive
5. Now create a new key by right clicking on Paradox Interactive and name that key East India Company
6. So now you're in HKEY_LOCAL_MACHINE -> SOFTWARE -> Paradox Interactive -> East India Company
7. Right click on East India Company and select "new" -> "string value"
Name that value "directory" (without the quotes)
8. right click on "directory" and select "modify". Now type the EIC-installation folder to the value data. For example:
"C:\Program Files\Paradox Interactive\East India Company" (again, without the quotes)
After that the patch should install fine.
