First, make sure that your computer meets the minimum system requirements to run Need for Speed Undercover:
- OS: Windows XP (Service Pack 2 or greater) / Windows Vista / Windows 7;
- CPU: Intel Pentium 4 or equivalent with 3.0 GHz for XP/ 3.2GHz for Vista;
- RAM: 512 MB of RAM for XP / 1 GB of RAM for VISTA;
- Video Card: DirectX 9.0c Compatible 3D accelerated 128 MB Video card or equivalent, NVIDIA GeForce 6600+ / ATI Radeon 9500+ / Intel G45 Express Chipset;
- HDD: 5.5 GB Free Space;
- DX: DirectX Version 9.0c.
If the requirements are fulfilled, its possible that the game files are damaged or corrupted. In this case, I suggest you update your video card drivers and DirectX and reinstall the game.