Q: I've downloaded about 10 gigabytes of arcade game software updates to my used PC, a Dell Latitude E6400. Recently the PC has slowed down, and I discovered that its hard drive was nearly full (probably the previous owner left some data on it.) Which files should I delete?
Tim Karash, Isanti, Minn.
A: Clearing files from your relatively small 160-gigabyte hard drive should speed up your PC.
As the disk fills, the PC will break up files into fragments to be kept in the disk's smaller spaces. But it takes the PC longer to reaccess such files. In addition, antivirus software takes longer to scan a nearly full hard disk, which absorbs processor time.
You can clear space on the hard disk by deleting data or uninstalling non-Windows programs. But don't get rid of any files that are needed by Windows or the programs you regularly use. Here's a list of things that you should never delete: (for details, see tinyurl.com/yb7kjotd):
• "Program files" folder: It contains your PC's programs and the Windows system files that allow the programs to work.
• "Windows" folder: Everything in this folder is needed to keep Windows running.
• "System32" folder: Located within the Windows folder, it contains vital operating software that handles things such as starting up your PC.