Terrible lag, please help?

[Exibitions]

Hello folks! Just got Just cause 2 with the new daily deals thing, and I've noticed some problems..mainly the god awful lag that means the starting cut scene took about 15 minutes to get through, and it takes a good 5-8 seconds for my camera or character to move when I tell it to.

My system specs:

AMD Athlon II X3 440 Processor

4gb RAM

Windows 7 64bit.

Hope I gave the right information there >.> If you need to know anything else just tell me what and how to find it.

How do I solve the lag? I have really been wanting to play this game, but playing it with this lag just isn't possible.

[Exibitions]

OS Name Microsoft Windows 7 Home Premium
Version 6.1.7600 Build 7600
Other OS Description Not Available
OS Manufacturer Microsoft Corporation
System Name DJ-PC
System Manufacturer MICRO-STAR INTERNATIONAL CO.,LTD
System Model MS-7551
System Type x64-based PC
Processor AMD Athlon(tm) II X3 440 Processor, 3000 Mhz, 3 Core(s), 3 Logical Processor(s)
BIOS Version/Date American Megatrends Inc. V28.2, 12/31/2009
SMBIOS Version 2.6
Windows Directory C:\Windows
System Directory C:\Windows\system32
Boot Device \Device\HarddiskVolume1
Locale United States
Hardware Abstraction Layer Version = "6.1.7600.16385"
User Name DJ-PC\DJ
Time Zone Mountain Standard Time
Installed Physical Memory (RAM) 4.00 GB
Total Physical Memory 3.75 GB
Available Physical Memory 2.27 GB
Total Virtual Memory 7.49 GB
Available Virtual Memory 4.66 GB
Page File Space 3.75 GB
Page File C:\pagefile.sys



If this is of any help >.>