Scan for viruses and malware. If none are found, great.
Turn off scheduled maintenance like disk defragmenter and system restore. System restore, when it decides to create a restore point, will slow the whole system down to a crawl by hogging all the available resources and it does this fairly often.
Make sure you have the MOST recent motherboard BIOS version installed.
Make sure you have the MOST recent driver versions installed for your motherboard chipset, LAN or WiFi network controllers, Audio controller and graphics card. Get the drivers from the motherboard or graphics card manufacturers website. If you have only integrated graphics, then get that too from the motherboard manufacturer, or laptop manufacturer's website and...