26 background services is about right.
Many of these are background services which run either automatically or are run as and when needed.
You can configure what services are run automatically by clicking Start, Run and type services.msc and press Enter.
click here to read up on the Services section. Also, click here
Many people like tweaking these services, and I've done my share, but I have to say it doesn't really make much difference to memory usage, for me anyway.
Automatic means the service is run automatically at startup. Manual means the service is run as and when needed. Disabled means it will not run at all.
Unless you are absolutely sure that you don't need a particular service (e.g. Telnet is not needed for most people), set it to Manual, and not Disabled.
Remember also that some services are dependent on other services. You can check dependencies by right clicking a service, selecting Properties, and selecting the Dependencies tab.