Why is my computer running slow after reboot?

Well basically this is the first time i have rebooted my laptop since i got it, (its a toshiba equium l20 197 with 1.25gb of ram instead of 256mb) anyway after the reboot its running really slow, jutters and stalls at every oppurtunity, i thought this might be because it had no drivers but when i went on the toshiba website to download the chipset and display drivers it keeps saying it can't install because in a nut shell the hardware doesnt match the software even though ive specifically entered my computers model number etc onto the toshiba site, any ideas on why its doing this and what can i do?