There are system services that you can disable to free up the system's load. To access the interface that permits you to make changes to system's services, type services.msc and the command prompt.
This is a list of services that are *usually* useless and can be safely disabled.
Alerter
Application Layer gateway Service,
Application Management
Automatic Updates
Background Intelligent Transfer
Clipbook
Distributed Link Tracking Client
Distributed Transaction Coordinater
Error Reporting Service
Fast User Switching Compatibility
IMAPI CD-Burning
Indexing Service
IPSEC Services
Messenger
Net Logon
Net Meeting
Remote Desktop Sharing
Network DDE
Network DDE DSDM
Portable Media Serial Number
Remote Desktop Help Session Manager
Remote Registry
Secondary Logon
Smartcard
SSDP Discovery Service
Uninterruptible Power Supply
Universal Plug and Play Device Host
Upload Manager
Webclient
Wireless Zero Configuration
WMI Performance Adaptor

*NOTE*: Make sure you don't need them since some applications you're using could depend on them. If you make any application to fail by disabling any of the services, go back and enable it again.