All I can say is I am glad I do not have an HP!
below is some useful info, for reinstalling, please read all and post back with any questions, but do contact hp as I could not find anything giving the exact instructions on how to reinstall on this pc.
Before You Partition or Format the Current Bootable Disk Ensure that MBR Security is disabled before you change partitioning or formatting of the current bootable disk. Some disk utilities, such as FDISK and FORMAT, attempt to update the MBR. If MBR Security is enabled when you change partitioning or formatting of the disk, you may receive error messages from the disk utility or a warning from MBR Security the next time the computer is turned on or restarted. To disable MBR Security, complete the following steps:
1. Turn on or restart the computer. If you are in Windows, click Start > Shut Down > Restart the Computer.
2. When the F10 Setup message appears in the lower-right corner of the screen, press the F10
key. Press Enter to bypass the title screen, if necessary. ✎ If you do not press the F10 key while the message is displayed, you must restart the computer to access the utility.
3. Select Security > Master Boot Record Security > Disabled.
4. Before exiting, click File > Save Changes and Exit.
http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c00709446/c00709446.pdf
user guide
http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c00072736/c00072736.pdf
more detailed guide
Shortcut to Temporarily Override Boot Order To boot one time from a device other than the default device specified in Boot Order, restart the computer and press F9 when the F10=Setup message appears on the screen. After POST is completed, a list of bootable devices is displayed. Use the arrow keys to select the preferred bootable device and press Enter. The computer then boots from the selected non-default device for this one time
http://h20000.www2.hp.com/bizsuppor...sId=316713&swLang=13&taskId=135&swEnvOID=1093
driver downloads for your pc
http://h20000.www2.hp.com/bizsuppor...p?&lang=en&cc=us&prodTypeId=12454&prodSeriesI
has a contact support link
http://forums.techguy.org/hardware/678915-hp-d530-sff-can-not.html
read this link on reinstalling on an hp
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further note, is everything working ok except for being unable to delete old drivers out of device manager?