The PSU in my Windows XP PC recently failed, so I went to a professional computer technician and he was able to move the contents to another case of mine which had a power supply.
My old PSU was from 2003, 350W and designed for a Pentium 4 system (which is what I've got) and the new one is from 1999, 300W and designed for AMD. The technician said this would be OK. My old case had a non-standard size PSU which would be very hard to find a replacement for.
The system now runs extremely slow when run normally (it's OK in safe mode) and I had to disable my Ethernet Controller to get it to start normally at all (I don't use it and it said there was a problem with it in device manager before the PSU failed).
If you move the cursor you only see it every couple of inches or so on the screen. If you click Start it'll take about 5 minutes for the menu to appear. It's incredibly slow. I just ran a checkdisk which took 5 hours and made no difference to the system performance.
Please can someone tell me how to correct this problem as I need it working again urgently.