As this is a Dell its probably loaded with various programs from the off.
Now you can reduce the startup programs from MSCONFIG,this may help.
I am guessing its a software issue,untick a few programs you recognise but not your synaptics or antivirus.If you have a third party firewall installed,leave this ticked also.
In your start box,type
MSCONFIG and enter.
Agree to the UAC prompts.
And select startup and untick those you may recognise and ok,goto General and do the same under selective startup.ok and reboot the computer.
Things like the below can be safely removed from startup;
some of the protection if freeware and not have realtime scanners etc.
Mobile phone software.
The list is endless.