If my answer was helpful, please use the 'Did this answer the question' and click: YesForum Member since 2001I am not employed by Dell
The only way would be to use your Dell system CD (XP MCE) you mentioned.
First, backup your important data.
Boot your system with that CD by pressing F12 at bootup and selecting your CDROM drive to boot from.
Follow the XP install prompts and you'll be able to delete your C partition, recreate and format it then install XP. Reinstall your drivers, apps and restore your data. An order of drivers I install is chipset, network, video, audio and modem.
NOTE Before you install XP: If RAID is enabled and you plan to continue using it, you will need to download the SATA drivers, extract the driver files to a floppy disc and during the XP install, press F6 when instructed to load the SATA drivers. If you do not want to use RAID, go into your system setup (F2), SATA Operation and set it to RAID/Autodetect ATA. This way you will not need the SATA drivers during your XP install.
Studio XPS 435T/9000 (His)Inspiron 1720 (Hers)Inspiron 530s (Server)