black screen with request for password

Well, reduced to this after over 10 attempts to contact Dell by phone (no returned calls) by chat (never worked until tonight. I was so relieved to get through only to read that I could neither chat nor email. Owned Inspiron I5 for almost 9 months and it has worked a total of one month during that entire time. OK I'm done bitching, to the forum if not to Dell. Had PC and worked for first 2 weeks and then OS needed to be re-installed. Dell sent me a flash drive but I could only run in safe mode with networking with the repair it offered. I guess they are only good for 1 install since I tried it again and I couldn't get any drivers and never worked after that. I ran it in Safe Mode for almost a month and the I turned on to spend another session if Safe Mode waiting for Dell to return call. One day about a month after partial installation I started it up to again run in Safe Mode only this time I didn't get Windows, I got a black screen with a weird looking prompt asking me for password, not in Windows, not in safe mode but just when turning it on. I have since tried every password I had used on accounts on PC and a few others in case I was wrong. I'd get 3 PWs in and get a response telling me I was locked out-again-never even reaching Windows. In fact if it weren't for On-button lit, I couldn't even tell PC was on. I kept trying with Dell but every time was when I was done work about 11:00 PM PST. Couldn't call, couldn't use chat most times because it had message that "Chat was Down". Emailed twice and now have no way of getting in touch aside from calling but I am at work and do not have PC with me, though guess I'll have to. Does anyone who frequents chat room know any of the answers to these questions 1) how to get through to Dell tech support after hours such as alternate email address? Has anyone ever seen this type of problem before and have any idea what it is and, more importantly, how to fix? Dell seems to offer plenty of self-service but it's all dependent on letting diagnostics access PC. Maybe I could find answers using those tools but since my PC can't get to Windows much less a browser , there's no way to know. Thanks. First timer who promises not to whine so much in future.