HP 9420, 18 months old and working perfectly. Battery decides for a while it doesn't want to charge beyond 60-85% or so. No problem because I use AC most of the time.

Then a few days ago the battery stopped charging and the machine switched off on 1% (while on AC). Ordered a replacement AC adapter and the machine booted up, but OMG how slow? 10 mins to load the desktop (as opposed to 40 secs normally). And it's running like an absolute dog; every screen update renders in slow motion, e.g. start menu, windows explorer, any other window or popup or dialogue box, any application, etc. It can literally take 5 mins to open a 2 page Word document, and even then the screen update is so slow it's unusable.

99.9% sure there's no virus on there because 1) it's running KIS and various malware/spyware apps, and 2) of the uncanny timing with the battery/power drain.

Is it a hardware issue? Battery? Motherboard? Or something else weird?

Warranty was only 1yr and not renewed. And no need for Apple fanboy comments.

TIA SM

Download Ubuntu and burn to a CD. Boot laptop from CD. Do you have similar performance issues?

Probably worth a re-install / repair if you have the Windows disk. Or System Restore to a date when it was all working fine.

full of fluff and overheating*

(*it's all I know, but I bet it's right)

Download Ubuntu and burn to a CD. Boot laptop from CD. Do you have similar performance issues?

Good point, I forgot to mention this. I've got copies of Ubuntu and XP Reatogo that I've used for previous recovery stuff. Tried Reatogo and the machine still behaves in the same way, hence methinks the hardware is somehow at fault. Ubuntu will be the same.

Probably worth a re-install / repair if you have the Windows disk. Or System Restore to a date when it was all working fine.

Don't have the original Vista discs and I never made a restore point. But the latter isn't really a problem because all data is backed up anyway.

The only (useful?) discs I have are:
HP Restore Plus (disc 1 of 3)
Vista SP1 (DVD 1 of 2)

Surely it's a hardware thang?

Cheers

and I never made a restore point.

I think it does that automatically doesn't it? So you should still be able to try it. I think the restore just reverses any changes that may have been made to the system settings, any installations etc which may be causing the problem. It's not about restoring data.

Having said that, judging by what you said now, it does sound like hardware. Worth a try though, a restore has sorted out 90% of the issues I've ever had.