Achei isso aqui sobre o modelo:
Sony Vaio VGN-FS 315N
Technical Data
Processor: Intel Pentium-M P740 (Dothan) 1,73 GHz, Centrino
Cache: L1: 32 KB, L2: 2MB, FSB 533 MHz, 915 Chipset
RAM: 1 x 512 MB DDR-SDRAM
HDD: 80GB, Ultra ATA/100
Graphic Card: NVIDIA GeForce Go 6400 with Turbo Cache up to 128MB graphics memory. PCI Express
LAN: 10/100 MBit Ethernet
WLAN: 802.11 b/g
Modem: international V.90, 56K flex
Display: 15,4-Zoll TFT x-black(2nd generation, double lamp technology), WXGA, 1280 x 800 pixel
Sound: built in stereo speakers, Intel High Definition Audio Sound
Interfaces: i.LINK (IEEE 1394), 3 x USB 2.0, earphone, microphone input, RJ11, display output, ethernet 10 BaseT/100 Base-TX, 1x PCMCIA Typ-I/II CardBus, Memory-Stick-Slot (Duo, PRO compatible)
Optical Drive: Double Layer CD/DVD +/- Brenner + RW für CD und DVD
Size (mm): 36,4 x 2,5-3,6 x 26,5 (mm)
Weight (kg): 2,9 kg
Essa especificação está dizendo que tem só 512 MB de Ram, entretanto, você disse num post (#28) que tem 2GB de Ram. Quanto tem realmente?