most netbooks uses 1.8 inch hdd including this one. i decided to replace it with a ssd but seems it's not so easy as i thought. Choosing the parts It's hard to find 1.8 ssd in market. also it will not be cheap even if i found it. Compact flash cards are fast enough as a ssd. they're widely using in professional photography. kingston 266x was my decision due to it's speed and price.

we need a 1.8 zif adapter for that, i found my cure at the dealextreme when i received the package at two months later, even i was forgot that purchase. poor me.
Installing OS Here is the tricky part, cf cards are usually appear as portable/removable drive in operating systems. and windows7 refuses install itself to a removable drive.

There are a lot of firmware tools on web which can convert cf cards to fixed drives. instead of that, i tried to forcibly install win7 via an alternative way and succeeded with that. a guy created an alternative installer for windows which can directly extract the .wim packages to target drive. he's not included the depencies in zip archive but complete toolset is available in here.
Results after the spending $25 plus three hours, got 3x more faster disk access and the annoying mechanical disk sounds are gone. due to nature of cf cards, writing speeds are low but that's acceptable.