Usually you would clean out unessary files, and programs which would make it alot faster. It may seem like it won't work but trust me it does. Hope this helps :)
No combat arms doesn't make your PC slow. Unless its a really cheap and old PC. It works really good on a HP laptop and doesn't affect it in any way. And if you don't want Combat Arms any more, you...
1. Slows your computer speed. 2. Decreases computer memory. ( By downloading patches, initial download/install, etc.)3. Could infect your system with virus, malware, etc. ( Because of direct...