Need help on help desk system

Hi try spiceworks, works great for me and it free

does inventory,
helpdeks,
purchasing, etc

But be aware that it has to poll the network at reasonable intervals to do it's best with reporting on your hardware and software inventories, and that can cause a few headaches.
This is just from experience on the network I last worked with.

We use Crow Canyon here. Seems to work well and meets our needs. It interfaces well with MS Outlook. Create tickets, assign them, email notifications, track time, etc.

http://www.crowcanyon.com/index.html

How many people must this Help Desk support? What level of expertise do you need? What is
the budget? If the budget is zero, you had better find someone who will work for the pleasure
of it.

Try Revelation CORE- completely free http://www.revelationhelpdesk.com/Core/Landing.aspx for up to five internal users and unlimited end users. There is an option to upgrade to their larger package but the free version is great for startups.

It has complete ticket history ??? each note is time/date/author stamped. You can create departments, sub-locations inside departments (offices, buildings, floors, etc.) and end users.

The paid version is not too expensive.

Hope this helps :)