|I've gotta go to bed after this (2.40 am UK).|
I'm assuming you are trying to bootup with a Linux Live CD in the drive (before power-on).
You have to get into BIOS first and set it so that the CD boots ahead of the HDD (C drive). Typically to get into BIOS you tap either F2 or Del key when booting. When you boot up you will usually see, quite briefly, some writing that usually refers to "setup" (which is BIOS) and which key you use to get there. This is well before Windows tries to start. This also applies if you are using an XP CD to re-install.
For Linux you need to burn "an image" onto the CD which hopefully is a feature of the burner software. It's not just a case of copying the download of the Linux Live CD onto it.
If you've any idea which files you deleted it will help - I've not a lot of faith in the Recycle Bin idea suggested earlier.
I'm off now and will pick you up again tomorrow. With luck some kind soul will take over in the meantime. Good luck - sorry if my explanations are a bit hasty and untidy - brain sleepy LOL.