So without firefox you are using 1.3 GB ram on windows 7, that is not really a shocker.
Clear out any unnecessary startup programs: you can type msconfig in start menu search but the better thing to do is download ccleaner.
Then clean out your system junk files, scan registry, and under tools you can disable unneeded startup programs there (anything related to antivirus is needed and anything for touchpad, audio, and intel chipset should be left on as well).