The MSI wnd has in built o/c capability upto 24% in the BIOS - the cpu can handle this no problem it can take upto over 100c plus the wind has better ventilation than most netbooks. - no real need to modify cooling - you can if you want but dont see the point as its sold with o/c capability. How did you upgrade memory - did you add extra 1GB or add a 2GB stick and disable the onboard. If your PC will not o/c stable at 24% with extra 1GB its probably caused by the mix of onboard (no so good quality) and extra 1GB stick. Best is add a 2GB stick - disable onboard (must do to boot) the o/c - should do 24% no problem. I run my at that all the time. Get lastest drivers for whatever system you have installed and optimise settings - plenty products around e.g Advanced System Care(free) - Tuneup 2009 (not free). I run Win 7 and it goes great once u tune/optimise settings and close unnecessary services.
The MSI wind U100 is the greatest netbook there is. You can make it faster for about 20% compared to the average netbook.
You have to use the correct ram to get the overclocking to run stable. Use 800 MHZ capable ram that has cas/ras times of 22.214.171.124 on 600 MHZ.
I use my MSI Wind for a year now on Windows Vista and runs swift and stable, No problem ever.
I have Asus netbooks too but the Wind is my favourite.