Computer woes

[lethargic_man]

My Windows laptop has managed to render itself almost completely useless, with very little help from me.^* :-(

So now I've got the question of what I do about it. Either I can spend probably a long time googling for solutions, with no guarantee of success; or I can pay through the nose to get the thing fixed at a computer shop (which I've not done or had to do before—and I have no idea how much thigs would cost; how much have such repairs cost you?). Or, alternatively, I can write off the ability to use Windows programs like Word for good, erase Windows and install Xubuntu instead. (I'd still have access to Word, etc, on aviva_m's machine, on request.)

Atm, I'm leaning towards the third of these, because atm Linux is annoying me less than Windows (or MacOS, which seems as unstable for me on my work machine as Windows was fifteen year ago); but it would be annoying to lose ready access (meaning: at in my lunch break at work, or any time aviva_m is using her machine) to Windows. Also, I've yet to find a music player on Linux that can play tracks without a momentary silence between (the one advantage Windows Media Player has over VLC)—anyone recommend anything?

* What happened is that in February Windows updates stopped downloading (progress downloading would stick at 0%). The laptop has spent most of the intervening time offline anyway (I took it to work, to listen to music on, because work won't allow me to plug a foreign device into my work laptop, meaning I can't get my music onto it, and I (still) don't have an MP3 player; and it doesn't recognise the guest wifi at work). But recently I did a bit of googling to try and solve the prolem, which suggested that I should use MSConfig to turn off non-Microsoft services and reboot. Lo and behold, when I did that, the large batch of updates pending already in February (it hadn't yet retrieved the ones from since then) downloaded as far as 68%, and then it put up a message about an invalid certificate. Unfortunately, after I noticed and dealt with this, it refused to download any further; and nor did it when I cancelled the update and tried again. But when I tried rebooting the machine, the moment I touched a key or the trackpad when the user selection menu was displayed to logon, the screen went blank and stayed that way; and this has happened every time I've rebooted since, except when I reboot into Safe Mode. But (a) I can't play music in Safe Mode (or I could live with the problem), (b) reverting to a previous state is broken, and (c) reinstalling Windows doesn't work in Safe Mode. And I can't do a clean install from DVD because I don't have a Windows DVD; I got the laptop secondhand with Windows preinstalled on it.