mouse trouble

Here is the issue; A friend just bought a new computer, so I got all his old hardware to upgrade mine. The motherboard was one of those new pci express ones, so I went out and bought a nvidia 7950. I formated and reinstalled windows after installing the new processor, motherboard, and video card. My mouse refused to move diagonally. It moves fine horizontally and vertically, but it stair steps in any diagonal direction. I thought it was the mouse going bad and always wanted a razor so I went and got one. It still did the same thing. Then I thought it could be the motherboard I got from my friend, so I went out and bought a new one... same after formating and reinstalling windows again even with a new motherboard. All drivers and firmware has been updated. The only thing that has stayed the same through all this is the video card and the windows disk i am using, everything else has been swapped out at least once and there has been no change in the mouse behavior.

Here are my specs:

Computer:
Operating System Microsoft Windows XP Professional
OS Service Pack Service Pack 2
DirectX 4.09.00.0904 (DirectX 9.0c)

Motherboard:
CPU Type DualCore AMD Athlon 64 X2, 2200 MHz (11 x 200) 4400+
Motherboard Name AOpen nCK804Ua-LFS (3 PCI, 2 PCI-E x1, 1 PCI-E x16, 4 DDR DIMM, Audio, Gigabit LAN, IEEE-1394)
Motherboard Chipset nVIDIA nForce4 Ultra, AMD Hammer
System Memory 2048 MB (PC3200 DDR SDRAM)
BIOS Type Award (06/11/05)
Communication Port Communications Port (COM1)
Communication Port Communications Port (COM2)
Communication Port Printer Port (LPT1)

Display:
Video Adapter NVIDIA GeForce 7950 GT (512 MB)
Monitor Plug and Play Monitor [NoDB] (QEW064800997)

Multimedia:
Audio Adapter Creative Audigy 2 LS Sound Card

Storage:
IDE Controller Standard Dual Channel PCI IDE Controller
IDE Controller Standard Dual Channel PCI IDE Controller
IDE Controller Standard Dual Channel PCI IDE Controller
Floppy Drive Floppy disk drive
Disk Drive Maxtor 6L100M0 (93 GB, IDE)
Disk Drive MAXTOR 6L080J4 (80 GB, 7200 RPM, Ultra-ATA/133)
Optical Drive SONY DVD RW DRU-810A
Optical Drive VERBATIM 321240AL (32x/12x/40x CD-RW)
SMART Hard Disks Status OK

Partitions:
C: (NTFS) 95597 MB (67746 MB free)
D: (NTFS) 76332 MB (14692 MB free)
Total Size 167.9 GB (80.5 GB free)

Input:
Keyboard Standard 101/102-Key or Microsoft Natural PS/2 Keyboard
Mouse HID-compliant mouse

Network:
Network Adapter NVIDIA nForce Networking Controller (192.168.0.100)

Peripherals:
Printer HP PSC 1600 series
USB1 Controller nVIDIA MCP04 - OHCI USB Controller
USB2 Controller nVIDIA MCP04 - EHCI USB 2.0 Controller
USB Device USB Human Interface Device

Any help would be greatly appreciated.