Lag spikes while driving

[asdeqw 0]

Yay, first post is a help question...

I recently got a new computer, and loaded GTA IV from steam. however, when I drive at any speed, it lags for about a second and then shoots forward.

Here's the diagnostic: (Well the start of it anyway, I'm too lazy to list the specs)

BEGIN *SIGNED* LCPD First Response Issue Report

Diagnostics Tool Version: 0.4.3

Operating system: Windows7 HomePremium (6.1.1.0 Build: 7601) Service Pack:Service Pack 1

System RAM (GB): 7.95

CPU cores: 4

NET Framework 4.0 installed: True

Visual C++ 2010 Redistributable installed: True

GTA IV - Installed: True

GTA IV - Install folder: C:\Program Files (x86)\Steam\steamapps\common\Grand Theft Auto IV\GTAIV

GTA IV - Version: 1, 0, 7, 0

GTA IV - Asi loader installed: True

GTA IV - Asi loader: DSOUND

GTA IV - Asi loader valid: True

GTA IV - C++ ScriptHook installed: True

GTA IV - C++ ScriptHook valid: True

GTA IV - C++ ScriptHook version: 0, 5, 1, 0

GTA IV - ScriptHookDotNet installed: True

GTA IV - ScriptHookDotNet valid: True

Am I being stupid? Is it just that it's crap on some computers? do I need it in compatibility? etc., etc.

The weird thing is, it's fine on my HP pavilion, admittedly with lower settings.

[asdeqw 0]

Okay, figured it out. (thanks for the help btw)

Turns out if the resoulution is too high, it lags, and so on.