Genrally when we are using the ORCLE 10G databse it consumes lot of resources of both memory and processors here is the small treak that will reduce this burden on ur personal PC.
step 1: Control panel->Administrative Services-> Services
step 2: Stop any services with the name of Oracle or something
step 3: u can optional set the property of these services to manual (by this u can prevent these services being load up at the system start up
Optional : u try to teminate the process JAVA.EXE from the task manager.
Note:Now when u want to work on database again then u now need to start these services once again.