First, unplug from AC, remove battery, leave battery out for now, plug into AC , try to boot normally. Start in safe mode with networking, by tapping F-8 at boot, Download, install,MIND THE FREE TRIAL PRO and UNCHECK, you want free MALWAREBYTES at :http://www.filehippo.com/download_malwarebytes_anti_malware/ . RUN a FULL SCAN, depending on the size of your HDD could take hours. DELETE ALL RESULTS. Download free CCLEANER at :
http://www.filehippo.com/download_ccleaner/. You can clean the junk from your system. TOOLS, STARTUP you can disable programs that startup at boot that are not needed. that's a start.