I put in an HP dvd200i, and am getting errors while writing to DVD+RW disks using the included software.

The software warns not to run other things in the background--which I don't. But I figure closing all but the necessary processes in the taskmanager might help.

My system is an Alienware DV2001 with P4 1.4Ghz/512MB RAM/40GB sys drive/2x60GB RAID 0 vid capture drive...

What are the only files necessary in the processes tab of the task manager? Should I log in as a power user or even a restricted user?

HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services would tell you what services are running. I doubt the problem is those services. HP is notorious for poor software and of including SCSI devices in their software where they are not needed.

In re-reading your post, since you are getting errors (and I doubt it comes from the background tasks. Right click on your My Computer icon, choose properties, Hardware tab, Device Manager button, the click on the + next to IDE ATA/ATPI controllers, right click on Secondary controllers (I am presuming this is how you installed it), choose properties and click on Advanced Tab. See if DMA is given your new device.