Wont Boot up! HELP

Ditto title above.

Sorry Bev. It was my poor attempt at a joke. I meant, I cannot figure out how to post a new thread on the forum and I did not want to interrupt the thread that was currently running. (Hence the reference to the title)However, now I have done what I did not want to do, I may as well jump right in. I have got some serious problems with my new Dell Dimension 3100c. Are you sitting comfortably? Then I shall begin. It all started when one day I tried to get on with my work. When I started my computer, as normal, it would not boot. In fact, it would try to boot, reset itself, try again and so on. I pressed and held the power button to stop this cycle and then finally managed to boot into safe mode. I had no idea what was going on and felt a strange sense of panic. I began to explore, hoping I would stumble across the cause. Big mistake! Some how I found myself in an unfamiliar place and there was all this stuff about permissions etc. I noticed that there were several user accounts. System, My own, all users, anonymous and one called, scarily, {unnamed] s-t- (something or other). Aha, I thought. Someone has has hacked me and opened a user account (I have heard since that panic creates mild paranoia and this is quite normal!). I then thought to myself, "well, I will stop your little game pal!" I began messing with the various controls to try and deny permission to the 'hacker' to use my folders etc. Little by little, the hole I dug for myself got deeper. As a result of this 'heroic' attempt to fight off a probably non existent hacker, I have now ruined all the permissions on the computer and can no longer access much of my files as I no longer have rights to them. I know. I know! I have called myself the same things! Anyway, is there a free utility that can make this all go away? What ever caused the problem in the first place also (and I noticed this before I set off on my foolish quest to thwart the 'hacker') changed my user account so when I logged on, my name, "George" no longer appeared. I was a guest on my own computer! If you can help I would love you forever (or Saturday. Which ever comes the soonest).

RE above:

I found this on the net. Does it make sense to you?

You will need to reset the NTFS permissions. This problem occurs when your folder is set private. You need to google NTFS permission reset. You will need Windows XP Pro or download a utility from microsoft if you have XP home that adds the security tab to the properties dialogue box.
The best third party tool I have found is Security explorer. You can download a 30 day trial.
It can also be done from the command prompt using a built in tool from Microsoft called Cacls.

Oh and........ I am running win xp home pack 2. on a dimension 3100c with a 17 inch flat screen monitor with no floppy drive. I do have a flash drive but no idea how to boot from it though.

Thanks for replying so quickly! I am impressed. Er, I can't do as you suggest because when I try to press ctrl+F11 nothing happens. I have timed this key press to perfection and released both keys together. I agree either a virus or worm is behind this. It may have been picked up the night before during a net session. I found myself on a weird Japanese site looking at all kinds of stuff (No! Not dirty stuff...TSK!) but as I could not understand a single word I was looking at I navigated by the "press it and see" method. During this process a file tried to install but I thought that McAfee had caught it. I guess not, huh? If I have to lose all my files I may cry but I will get over that. Most of the important stuff is already backed up. So, whatever has to be done.......

Hi Bev Thank you for your patience. This morning a friend brought me a floppy drive and installed it. It is working ok. I also have an old win 98 boot disk. I am told that with this boot disk I can use fdisk if I have too to change the partitions into Dos based partitions. I don't really want to do this unless it is a last resort but I will if that is my only choice. Where can I obtain the re installation disk? I have also been told that somewhere there is a utility to replace the permissions on the drive and to repair the XP recovery partition so it can be used again. I will go in search of that but if you know where to find it, that would be great. Thanks Bev. Your time and help are greatly appreciated.