BOOTMGR is missing Press Ctrl + Alt + Del to restart

Hi All - I've searched the forums but can't find a solution to my problem (please forgive me if there is already a thread on this dealing with Windows 7 x64). I have a newly built system (5 weeks old). Everything worked perfectly until I purchased an upgraded video card. After installing a new graphics card, my PC would not boot - it stopped at "DISK BOOT FAILURE, INSERT SYSTEM DISK AND PRESS ENTER". Mind you, the ONLY thing I changed was pulling out a Radeon 5770 and replacing with a Radeon 5850 (no need to remove and reinstall Catalyst drivers since both cards use the same drivers) - again, NOTHING was changed in my system before and after the gfx card swap. I disconnected and reconnected my HD cables, cleared the mobo CMOS and tried again - I then got "BOOTMGR is missing Press Ctrl + Alt + Del to restart". I attempted all the command line bootmgr fixes I could google - all to no avail.

So I brought my pc in to Microcenter where I purchased all the parts - they helped me troubleshoot it last night for several hours. We checked all connections, pulled the HD (Win 7 boot drive - the only drive connected) and check that the HD was OK on another system - it found everything and it looked healthy. We checked BIOS to make sure everything was OK - still got same error. Replaced and rechecked all HD and DVD drive SATA and power cables. Still had same error, so they swapped my WD Caviar Black 1 TB for a new identical drive. We attempted to install Win 7 on the brand new drive - once Win 7 did the normal restart part way through install, it gave me "BOOTMGR is missing Press Ctrl + Alt + Del to restart" AGAIN!!!!

So, having an old IDE DVD/CD drive in the pc that sounded like it was no longer happy, I bought a new LG super multi DVD writer (SATA this time) and installed that - again rechecked ALL connects in pc case (also disconnected my internal media card reader, just in case that was an issue). I still get the same "BOOTMGR is missing Press Ctrl + Alt + Del to restart". I followed the instructions to torrent a Windows 7 x65 Recovery CD - I tried that, but same Bootmgr missing error - basically, the pc will not get past that error anymore - it will NOT run from DVD/CD at this point - just stops at "BOOTMGR is missing Press Ctrl + Alt + Del to restart", so I thought of using EasyBCD to try repairing this, but since I cannot get into Windows or even run a CD on it, I'm totally stuck.

Is it possible that something went bad on my Motherboard once I rebooted after installing the new video card? (we tried connecting HD's and DVD to multiple combinations of SATA connections on the mobo, but that didn't make a difference).

Thanks in advance for anyone that can help with this. FYI - I am unable to get into the BIOS when I'm at home, because it appears my (new) Gigabyte GA-P55 UD3 motherboard won't do anything when I use a USB keyboard - the only way BIOS responds on it is with a PS/2 keyboard they used at Microcenter (any ideas on why that is the case, I'd also love to hear - how could a mobo purchased in 2010 still require a PS/2 keyboard to work in BIOS? That just crazy talk!).
What do you mean to have it boot from the USB CD first? Do you mean I need to change the BIOS to boot from the SATA DVD/CD first? (because I don't have a USB CD drive - only a SATA internal DVD/CD writer). Thanks!
Thanks for that help. Here's where I am now. Microcenter swapped my mobo for a fresh one and they formated the HD that I will be installing Win 7 on again (get this - they have pc's all over the place, but the guy formatted my HD on a Mac so he could only format in FAT32! That was encouraging!).

Anyway, I have now gotten everything screwed back together in my HAF922 and am loading Win 7 again - yes, it appears the original mobo had gone belly up on me (disk controller issues or something). Of course, since this was my first DIY pc and now I have a second chance at putting it together, I have learned some things - learned the correct way to apply thermal paste (instructions that came with the Intel processor and the Thermaltake cooler didn't provide much useful info - Googled 'how to install thermal paste' and watched several Youtube vidoes - amazing what you can find on the internet these days!) - I also realized I could route my cables much better so had a chance to redo that also.

So many thanks to you - and good gaming (or productivity) to all of you!:booyah:
Hiyya fattuesday, glad to hear your up and running once more.

DIY PCs are incredible :smile: always fun, and ever so informative!