Junk (go ahead and delete any wierd little files you can’t identify)
Unknown Files ending in .exe These may be malware that caused your problem)
Delete everything you can’t identify (Except if it is in a trusted vendors folder, than scan)
When downloading files in the future, look for information about “mystery” files that you don’t know much about. Make sure to scan them with AVG or another virus scanner. Take caution opening old files, and care about your computer’s well-being.