You certainly do not believe in giving out to much info,do you? Basic stuff,what make/model of PC? what operating system? how long have you had the PC? have you run various anti-virus,spyware,malware programs.
Have you thought about backing up your personal files and doing a complete reinstall of Windows?
You say you have removed/deleted 1GB of stuff, if you have a 60SSd then that would be a lot, if you have,say a 500GB hard-drive that is nothing.