I have a 7742-CTO purchased December '07. It has Nvidia Quadro NVS 140m, preloaded with XP Pro. Now that is out of warranty, it has started randomly freezing. It doesn't matter if the R61 is plugged in or on battery, being used or idle, time of day, etc. This is typical scenario: I look at the Windows time in the system tray and see that it is incorrect (stuck at time of crash), mouse is movable but the next click will freeze/hang the system. Only fix is hard reboot. The freeze frequency has gone from once/week to several times/day.

Next, let me say that I have a lot of technical experience with PCs. The BIOS and drivers are all the latest from Lenovo. All critical Microsoft updates are applied. I have scanned for viruses and malware as well as scrubbed the registry. In addition, here are some of the other tactics that I've tried:

1) Fully tested RAM

2) Tried different RAM

3) Swapped AC adapters and tried both battery inserted and battery removed

4) Different hard disk drives

5) AHCI changed to compatibility mode

6) Removed, inspected and cleaned fan-heatsink assembly

7) Redid thermal conductive grease on CPU and GPU

8) PC Doctor diagnostics on the system turned up nothing

9) Disabled Nvidia startup items and NVSC Service

I even tried diagnostic startup using MSConfig and minimal startup items and it still freezes. I suspect that the NVidia NVS 140m GPU is bad. Anyone out there with similar problems?