First, you will need to get ColdFusion pointing back to the original JVM. Open the jvm.config file found at C:\ColdFusion10\cfusion\bin using a text editor. Near the top of the file, look for the line that starts with "java.home=". Change the path to "C:\\ColdFusion10\\jre" (don't use quotation marks around the path). Save and close the file. Now try starting ColdFusion.
Second, you can't use the Java JRE that comes in the standard Java consumer download. You need to download the Java SE Development Kit (JDK), which contains the JRE and some server components that ColdFusion needs. You can get the JDK here: http://www.oracle.com/technetwork/java/javase/downloads/jdk7-downloads -1880260.html. Download and install the appropriate JDK for your operating system. You should now have both a "jre7" and a "jdk1.7.0_XX" folder inside of "C:\Program Files (x86)\Java". Now follow Peter's suggestion on updating the JVM setting in CF Administrator.
-Carl V.