I have a Mini 9, which is only superficially different from your Vostro A90. Mine has a 4GB SSD
, and I've upgraded the RAM to 2GiB.
As for space, a large SDHC card might satisfy your needs. I use a 8GB card to store media, while the 4GB SSD
stores the OS and apps.
As for memory, just about any DDR2 laptop RAM will work. Your netbook has a single slot, 2GiB is the max module size, and 533MHz/PC2-4200 is the minimum
speed the RAM should be. Faster RAM will work, too, just not at its full speed. My Mini 9 came with 800MHz RAM and now it has 667MHz RAM, but both only run at 533MHz in the Mini.
Upgrading the hardware in the Mini 9/Vostro A90 is easy. The SSD
, WiFi, RAM, and WWAN/cellular Internet card (if present) are all under the access panel on the bottom. The RAM is just secured by spring-loaded tabs. The SSD
is just secured by two screws. The hardest part of installing a SSD
is reinstalling the OS and apps on the new drive, not the physical installation.
Good luck with whatever you do.