A friend, who is looking for a Sony Vaio laptop with a fast, 5,400rpm hard-disk drive, was told that a model from the same brand with a 48-gigabyte Flash Memory drive runs faster. Is there a faster hard-disk drive-based Sony notebook available? Daryl, Causeway Bay DQ: I believe your friend is too concerned with the specifications of the disk drive. Notebook computers essentially come in two flavours: ultra-portable and desktop replacement. The latter machines have faster processors, large screens and are a bit heavier than the typical laptop. They do just about everything a desktop computer can do. The ultra-portable notebook computers are small, weigh as little as possible and everything in them tends to be smaller and slower. The processors perform slower - so they don't use as much power - and the same is true of the hard disks. The speed gain your friend thinks he will get with a 5,400rpm hard-disk drive could well be minimal. The Flash Memory drive should be much faster, but if the processor is slow that speed advantage may not matter much. I think he should decide what is more important: size and weight, or performance. If he really wants the performance, he may have to look at a bigger machine. I have downloaded the ParetoLogic RegCure software, which is supposed to optimise the performance of my personal computer. Will installing this affect the operation of Symantec's Norton Internet Security software? Name and address supplied DQ: Theoretically, RegCure should help you clean, repair and optimise your machine's hard disk without interfering with anything else. But you are wise to be concerned. The best way to handle this is to shut your computer down and reboot it with as few programs operating as possible. Disconnect from the internet, turn off all applications that start automatically at boot time, and make sure nothing is running, apart from the operating system. (Right click on the clock and select Task Manager to see what is running.) You can turn off your Norton software because you are not connected to the internet. Run RegCure and when it is complete, reboot the machine, making certain your internet-protection software is running again. Then you can connect to the internet, confident that all is well. RegCure has a good reputation and will certainly speed things up. Just make sure you turn that internet protection back on before reconnecting to the outside world.