That's disappointing 
A few more ideas:
You do have Vista updated to at least SP1?
You aren't overclocking the CPU by any chance?
What PSU are you using? You might double check that all cables/plugs are firmly secured to the video card.
Are you launching crysis with the x32 or x64 .exe? Whichever one your using, try using the other.
Have you tried temporarily downclocking the card yet? It may worthwhile as a test.
To rule out RAM being an issue, it may also be worthwhile running memtest86+ overnight to see if it throws up any errors at you:
Memtest86+ - Advanced Memory Diagnostic Tool

A few more ideas:
You do have Vista updated to at least SP1?
You aren't overclocking the CPU by any chance?
What PSU are you using? You might double check that all cables/plugs are firmly secured to the video card.
Are you launching crysis with the x32 or x64 .exe? Whichever one your using, try using the other.
Have you tried temporarily downclocking the card yet? It may worthwhile as a test.
To rule out RAM being an issue, it may also be worthwhile running memtest86+ overnight to see if it throws up any errors at you:
Memtest86+ - Advanced Memory Diagnostic Tool
My Computer
System One
-
- Manufacturer/Model
- Self Built
- CPU
- i7 3770K HT ON 4.7GHz
- Motherboard
- P8Z68 Deluxe Gen 3
- Memory
- 8GB G.Skill Ripjaws X 2133mhz
- Graphics card(s)
- 2x Gigabyte GTX 670 OC WindForce SLI
- Sound Card
- X-FI Forte + ATH-AD900
- Monitor(s) Displays
- x2 Dell U2410 / 58" Samsung / "40 Sony
- Screen Resolution
- 1920*1200 / 1920x1080
- Hard Drives
- 2x Intel 520 240GB * Crucial M4 128GB * 2x Samsung F3 1TB (RAID 0) * 2x WD Caviar Blacks 2TB (RAID 0)
- PSU
- Corsair AX1200W
- Case
- Lian Li PC-V1020A
- Cooling
- NH-D14: 3x140mm Gelid Wing 14: Sunbeam Rheobus Extreme
- Mouse
- Razer Imperator + Thermaltake Theron
- Keyboard
- Topre Realforce // Ducky Shine Cherry MX Black
- Other Info
- Laptop Specs: Clevo Sager P170HM // 17.3 Matte 1920x1200 // i7 2720QM // 8GB 1333mhz // Dedicated GTX 485M // 240GB Intel 520 + 750GB + Blu-Ray // Samsung Story 2TB USB 3.0