Hello Rachel,
* Make sure you do your computer housework on a regular basis.
If you do everything should be ok.
Eg
Check Disk.
Defragment
Disk Clean Up
Temporary Files Removal
http://www.microsoft.com/athome/setup/optimize.aspx
* IE.- Safety - Delete Browsing History.
Check for unwanted plug ins.
* If necessary > Open IE
* tools
* internet options
* advanced
* reset
* Make sure your Windows Update is running.
All programs MUST be updated regularly.
* If overclocking stop.
* On a regular basis check in Task Manager/ Processes/ All Users to see what is running there.
* Check in Event Viewer for errors frequently.
Note anything with a red mark Windows Logs, Application & System.
* Monitor regularly >Perfmon - {Task manager - resource monitor - CPU, Memory etc}
* Remove any software you have evaluated and decided you don't want to keep.
* If necessary >Run: SFC /scannow (from a command prompt) - and let it check/repair/verify your system files
*Some people optimize and compact the registry.
This makes me VERY nervous and consequently I don't.
*Re Registry Cleaners -
Registry Cleaners are often considered to be helpful, but if you are a novice probably best avoided.
They can cause loss of functionality and/or system instability.