After the 10 steps mentioned before in my previous post but your PC still consider slow, then you can try another 10 steps for better speed.
1. Use Intel Application Accelerator to speed up your disk access.
2. Memory management (at least 512MB RAM Required). This allow XP to keep data in Memory instead of paging section of RAM.Go to->Start->Run->regedit->HKEY_LOCAL_MACHINE->SYSTEM->CurrentControlSet->Control->Session Manager->Memory Management->Double click it->DisablePageingExecutive->Double Clik it->Set value to 1.
3. Disable Yahoo Messenger, Google Talk, and other unwanted programs from startup(You can do this through registry editor). Because they do not appear in normal Startup Option.
4. Disable indexing files service (only if you do not use search option regularly). To do this follow the following steps.Go to My Computer->Select the drive for which you want to disable the indexing service->Properties->Unselect ‘Allow Indexing Service’->Ok.
5. For Windows XP, You must use NTFS partition. FAT partition is less supportive for Windows XP.
6. In BIOS, Select first booting device as your HDD.
7. Setting Priority High for a particular program.Open Task Manager->Processes->Select the desired Program->Right Click->Set Priority->High->Ok.This Priority set if for current session. Once you restart your system then its priority will again be Normal.
8. Keep deleting your Temporary Internet Files and temporary at regular intervals.*Go to Programs -> Accessories -> System Tools -> Disk Cleanup.*Now select a drive to cleanup.*After that click “OK”.*Now clean up unwanted things like “Temporary Files”, “Recycle Bin” and click “OK”.
9. Empty your browser’s cache at regular intervals because it can slow your computer. Removing the browser’s cache will also free up some disk space.
10. Avoid keeping Movies in your PC. Remove any unwanted movie(s) because this can free up a lot of disk space and make your computer fast. And avoid downloading movies from the net because these carry viruses, spywares, etc. many times and can slow down and can also infect your computer.
Well, hope this can help you. If not, you might need to consider to upgrade your PC.