well.... what u wanna do is:
1. delete all unnecessary progs from ur computer's hard drive.
2. http://www.download.com/Registry-Mechanic/3000-2094_4-10566526.html
3. remove unnecessary progs from ur system tray
Reduce your boot time:
* Check the BootOptimizeFunction registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Dfrg\BootOptimizeFunction. If the Enable string value is not set to Y, change it. (This is enabled by default.) Exit regedit and reboot. A boot up defragment will now take place. This will optimize the position of the boot files for a faster boot.
* Purge Prefetch? I’ve found that after purging C:\windows\prefetch my system takes longer to boot. Admittedly, it is a delay of only few seconds and things normalise after the use of the computer over a few days. An exception is to clear out obsolete .pf files referring to programs that have been uninstalled. For more details, please see the March 2005 APC.
* Check the BIOS: Look for quick Power On Self Test (POST), and Boot Delay enabled. (On pressing the power button you will have to quickly press one of a number of keys. Esc, F1, F2, F10 and Delete are commonly used. It varies according to the BIOS manufacturer.) If you never use a floppy drive, turn off the option for seeking a boot up floppy.
* Completely defrag your boot/system drive: Unfortunately, the defragger provided in XP is a limited version of Executive Software’s Diskeeper. Opinions differ as to the best defragger for XP. Popular choices are Diskeeper, O&O Defrag and PerfectDisk. Worth investigating is a good, full-featured defragger available from: http://www.whitneyfamily.org/Hacks/?item=Defrag. This is a complete defragger. Multiple instances can be run simultaneously (if you have multiple disks). It features individual file defragging, with wildcards and recursion and will defrag NTFS, FAT and FAT32 file systems on any media (HD, Zip/Jaz, floppy, etc). Depending on the size of the hard drive, its free space and the number of files involved, this can take several hours. Planned for a future release is the defragmentation of NTFS metadata files.
* Remove the garbage and optimise the registry: Be very wary of know-all, do-all, and promise-all registry cleaners. Your choice should have an undo function. Norton One Button Check Up/Norton WinDoctor have their devotees. The freeware EasyCleaner available at http://personal.inet.fi/business/toniarts/ecleane.htm is more aggressive than these Symantec products, but when used carefully is beneficial.
* Use a Registry Optimiser: Download the excellent freeware program Erunt V. 1.1h from http://www.aumha.org/freeware/freeware.htm. This includes a tool for backing the XP registry and one (NTregOpt) for optimising it. NTregOpt optimises by compacting the registry hives to the minimum size possible.
* Malware problems: In addition to full AV scans, regularly use at least two recognised spyware/adware removal programs to check your system for nasties. The free Microsoft AntiSpyware Beta 1 is commonly regarded as an excellent product.
Eliminate unwanted programs loaded during boot up: Run msconfig to access the system configuration utility and press the start up tab. This gives access to started applications running in the background. By researching filenames and folders, you can get a feeling for what is unnecessary. Viruses and worms can hide and disguise themselves with authoritative sounding Windows system file names. If you are unsure do a Google search and if uncertain leave alone. The Start Up folder can be a depot for nasties, so research any unrecognisable shortcuts as Windows does not place critical files in this folder. A very useful listing of essential, non-essential and harmful start up programs is available at http://www.pacs-portal.co.uk/startup_index.htm
· Disable unnecessary services: Windows XP runs many services in the background. Disable those that are not actually necessary for the day-to-day operation of your PC, but do your homework first! Careful research is necessary here, depending on the work done by your computer. A comprehensive Services Guide for Windows XP is at http://www.theeldergeek.com/services_guide.htm. The Indexing and System Restore services can occupy a lot of disk space and system resources. The Indexing service is not crucial. However, keep using System Restore (or its equivalent) as it can be a life saver. Loss of boot up speed may not be worth the consequence of crippling System Restore.
· Disable unneeded devices in device manager: For a quick fix disable any unused devices in the XP’s device manager.