Errors after shrinking the operator volume C in windows 7

Hi every one, I am using a desktop of my university in my office. Because it has only 1 volume C with 450gb space, I tried to shrink it to get another volume D by using the Device management on Windows 7 (computer manage -> device management). It still work after I restarted. Now, when I restarted, there was only a long beep and no thing happened. Could some one help me, please? My desktop is: Dell, model 7020, windows 7 professional 64 bits. Thank you!

A reference guide to the OptiPlex Diagnostic Indicators | Dell US

I assume this is an Optiplex 7020?

Above link is to beep codes for Optiplex models. Unfortunately, I do not see a code for one single long beep.

Maybe someone else has a better idea.

Try booting into Dell Hardware Diagnostics from F12 Menu by tapping the F12 key at boot. Run Diagnostics and if there is a Utility Partition the additional diagnostics from it.

If hardware checks out then proceed with Troubleshooting Windows 7 Failure to Start.

If hardware does not check out then try booting into BIOS setup to confirm the hard drive appears there. If not check its cable, try running the maker's HD Diagnostic CD scan, or replace it. The best replacement for a hard drive is an SSD, faster than a high-end replacement PC without one.

I tried with F12, Delete, F2, F8 but it didn't work. No thing happened. Finally, it appeared that: press F11 for recovery but no thing happened again when I press F11. It is a new computer.

I just told you what to do next then. Any questions?