What do you do when your computer won't boot, your most recent backup is three months old, and you don't have an emergency CD? What if you're us¬ing a laptop that doesn't even have a CD drive? Kiss your data goodbye-or just whip out the bootable USB key (or thumb drive) you prepared in advance. The key will boot into a free Windows¬based system called BartPE (that's Bart's Preinstalled Environment), devised by Bart Lagerweij, from which you can copy files on your hard drive to the key or, in some cases, send them over a network to another machine.
Now, not all computers can boot from all USB keys; you'll need to experiment with yours-unfortunately, there's no way to predict if it'll work.

The tools you'll need are a USB 2.0-compatible drive with 256MB or more of storage space; a Microsoft Windows XP installation CD with Service Pack 2 (see step 1, below, if you don't have a Win XP CD with SP2); and Bart's PE Builder, from Bart's Preinstalled Environment, For faster booting on some but not all systems, you can try FlashBoot , which automates the process of installing the BartPE environment to a USB key.

Before booting from your USB key, 10-cate your PC's BIOS settings and explore the menus to find the USB settings, or possibly the boot order settings, to add the key to the list of boot drives (write down any settings you change, in case you have to restore them later). You may need to specify that a USB key will be read as a hard drive, not a "super¬floppy." One important note: There's a serious security risk involved in allow¬ing your PC to boot from a USB key¬anyone with a bootable key can take ad¬vantage of the capability.

Select Columns

Because we're focusing on performance, start by right-clicking on any column header, then choose Select Columns, then click the Process Performance tab. Place a check next to CPU Usage and CPU Time. Click on the Process Mem¬ory tab and place a check next to Virtual Size.
Enable DMA

Amazingly, some Windows XP systems are not configured to use DMA, a mode in which your hard drive bypasses the CPU and accesses memory directly from RAM. DMA enables the CPU to work less and therefore faster. Go to Device Manager (Control Panel I System I Hard¬ware I Device Manager) and look for the IDE ATA Controllers section. Click the Plus sign, then double-click Primary IDE Channel. Click Advanced Settings. Make sure the DMA option is selected for both Transfer modes. Click OK. Repeat for the Secondary IDE Channel. Click OK.
View Columns

Click on any column heading to sort by that column. For example, if you click the Virtual Size header, you will see the most memory-consuming processes list¬ed first. Click the CPU header and you'll see processes that are using all the pro¬cessor power on your Pc.
Kill Processes, carefully to end it. But be careful! If you kill a pro-cess that Windows needs, your PC will crash. Searching a process name online should turn up what it does and whether it's safe to kill.
Convert to NTFS

NTFS (New Technology File System) is, as its name implies, a faster file access method than FAT (File Allocation Table). You can convert to the newer standard even if the hard drive you have is using FAT. Just go to Start, then Run, then type cmd. Type convert drive_letter: /fs:ntfs into the command line, where drive_let¬ter is the letter for your primary drive. Press Enter. Warnings: Some DOS and older Windows apps can't read an NTFS drive, although there are utilities to overcome that problem. Also, you can't convert back to FAT. Finally, the conver¬sion can take a while, so sit back and count ceiling tiles while you wait.