Step 3: Clean Out Your System Junk (Temporary Files and Folders) With Disk Cleanup (cleanmgr) Over time, your computer accumulates junk files from normal web surfing and computer use. If this junk isn't occasionally cleaned out, it can cause AOL 9.0 Optimized to respond slowly or provides an KILLERSEG5.JS error, possibly due to file conflicts or an overloaded hard drive.