OK. Let's see if I can help. First, you left out some info folks need to know in order to help. 1st- When you installed deb, did you elect to NOT install the bootloader to the MBR (Master Boot Record). (What boot loader do you use, by the way)? If you elected no, then there's your problem. You set it up to boot from floppy. If you elected yes, then there is another problem beyond my ability to help.
2nd- If you are using lilo or grub bootloaders, there is documentation available all over the web to instruct you on how to reconfigure the bootloader to boot from hd, with the floppy as a backup means to boot. Check this and other Linux bulletin boards for help files aimed at helping newbies with installation and configuration issues. Use the search functions at those sites, and search the threads regarding your bootloader.
3rd- what do you mean, 'how to get into a window manager'? Are you booting to a text-only mode (no graphics)? If so, you are booting to runlevel 3 (text mode). Enter the command 'init 5' and press enter to complete the boot process to graphical mode and a login screen. To make the command permanent, use any of the text editors supplied with deb, and edit the file /etc/inittab. Edit the line 'id:3:initdefault:' to read 'id:5:initdefault:'. deb installs a default window manager.
Or, do you mean 'how to get into a file manager'? If so, look to the system tray for an icon (probably a house) representing your home directory. Click on that, and you'll be in the file manager.