Windows XP SP3 - Services are set to Automatic but don't start

##Saw the other post with the same problem. Guess I will try re-installing windows

I recently re-installed windows XP with service pack 3 on my computer. When I tried to install programs or use the internet I would always get errors saying the services werent started.

So I checked in the Services manager, and while the required services are set to automatic, they aren't started. I can manually click 'start' and the services will start, and I can run programs. But this is a hassle to do everytime I restart my computer.

For instance, windows installer service is set to automatic but unless i manually click start, I can&t install programs.
Also windows wireless, network connections etc. They are set to start automatically but unless I manually tell them to start everytime, I can&t connect to the internet.

I have used windows update and downloaded every update, but it still hasn't help.

Does anyone know a reason why my services won&t automatically start (even though they are set to automatic)?


**There are about 10 or 20 services set to automatic that don't start (RPC, my virus scanner service, windows defender etc - I scanned for viruses after manualy starting the service but this didn't help) --- but it is strange because some services do start automatically (eg Plug and Play)

Any help would be appreciated! been at this for a few days and not making any progress

Windows Installer is usually set to manual, anyway.