Cannot start the RPC Service, Error 5: Access is denied?

I had Windows Xp and I installed Windows 7 and Recently I dual booted my Pc with EasyBCD 2.0. Now I found that when I went onto Windows Xp that all of the temporary files were locked and I entered safe mode and after a long process (7 hours) I finally fixed all the temp files. Now the user I could go on now had access to the temp files but still when I try to open up browsers they all close and when I try to install stuff I get different errors but what I found out that's wrong is that the cryptographic service isn't running so I try to run it and I got an error and so I looked it up and it says that the RPC service needs to be started. I find the service and try to run it, however I get another error, Access is denied, so then again I look up a fix and find that if i delete the security properties in regedit that it will reset the permissions. I do that, turn off the computer, turn it on try to start the service and now it says it failed to start but it returned no error, then I try to start it again and now it says access is denied does anyone know how to fix this?