BOOTMGR is missing and windows won't boot

My Acer laptop has been affected by virus and it even did not give me an option to boot from the boot manager, when I try to press F2 for my boot menu it did not work and instead the windows starts always, so I have directly install the windows form DVD option. I have successfully installed the new windows and even did delete the windows.old folder from C: Drive and installed the MS Office pack, but later the charge was over and it got shutdown and when I plugged in the charger I got this message saying BOOTMGR is missing. I thought of booting again but the boot menu doesn't come only the logo of acer, I have tried hitting CTRL+ALT+DEL for several times but it gives the same message. I even tried with the F8 key but no luck.