building daughter pc need help

What is your budget? Your best bet would be an Intel Q6600 or an E6750 depending on your budget. I'd suggest the ASUS P5K-E because it has 3 PCI slots and onboard firewire. The latter would be if you have a digital camcorder or planning on getting one plus if you get an external hdd with a firewire connection and save a USB port. Suggest 2 hdd a smaller one, like Seagate, for the OS/programs and the second for storage. Kids are malware magnets , they help themselves and this will make it a lot easier when she (you) have to reinstall Windows. I such you have have her build it including having install Windows and driver. Just did this with one of my granddaughters who's a freshman. I was there but other than a minor driver issues she didn't need my help. Even though she's a cheerleader she liked the geek cred that came with building among her peers.
http://www.newegg.com/product/prod [...] 6813131225

^Agreed. You can also switch the CPU to the E6550 and OC it. (If OCing you need to get a better cooler). To back up just the OS you can also use the Xpress Recovery option on the P35-DS3L. (Read the Manual for more info; here is the link (Pg. 57):
http://www.gigabyte.com.tw/Support [...] leID=18097 )

Software wise, get XP x64 if possible, or Vista x64. You might also want to try out Maya, which is a great program for 3D work. If this PC is only for Photoshop,etc work and not much gaming you can degrade the graphics card a bit and up the CPU to a Q6600. (Photoshop CS3, SolidWorks,Maya,AutoCAD,etc really benefit from a quad core)

Akhilles has a good build right there, but I'd replace the E6750 with a Q6600 for graphics animation... video editting, sound chopping and clipping will be very taxing on the processor, not so much when doing the editting, but when doing a draft- or final-render, it'll be a lot faster (with the newer software, of course) to have the quad-core...

and he makes another great suggestion with Acronis True Image... I WOULD install it, though, and schedule it to create the automatic backup for you after your malware scans (automate them, as well)... make sure you backup to a DIFFERENT drive, because it's not really a backup if you don't, and data recovery (not transfer, but RECOVERY from a dead drive) starts at $250 for evaluation and can range from between $500 to $5000+ for resurrecting data from a dead drive... (prices vary based on region and company doing the repair)