ntldr is missing

I received a custom built destop computer as a gift from a family member running windows 7. virtually every day i get a black screen saying ntldr is missing please reboot, but I have to do a complete cold boot. a ctl-alt-del boot won't do it. I have tried in vain to correct this issue for 2 years. i don't have the windows 7 disk and neither does the gifter. Any ideas on what to do? Thanks in advance. Mickey

Please post back a screenshot of Disk Management - Post a Screen Capture Image.

Try running a few Startup Repairs using a System Repair Disk to see what it finds.

Is there a COA sticker affixed to the machine showing that the Win7 installed upon it is Genuine? If not were you provided with this documentation? I'd ask the giver for this since it has a $100+ value and should be provided in case of reinstall.

If assured it is Genuine retail, you can also audit the Product Key from the drive using Belarc Advisor. Does the Product ID at Control Panel>System have an "OEM" in its string? This could be a complication. If not the Product Key can be used for reinstall if needed.

If you have the habit of leaving USB flash drives/USB HDD plugged in the system, this can happen. Windows may try to boot from the USB instead of internal HDD and may display the error message. Make sure to unplug every USB storage devices before powering on the system.

It may have XP code still on the drive so would be best to do a Clean Reinstall - Factory OEM Windows 7 if he has a legal Product Key, making sure to delete all partitions during the booted install.

Otherwise there's a possibility Startup Repair can sort it out. We need to see the Disk Mgmt screenshot to confirm the config and partition marked Active. Disk Management - Post a Screen Capture Image