Both laptop and dekstop frozen at same time
Need urgent help please.
Yesterday my Samsung Laptop Windows 7 and wifi froze after startup on the desktop, eventually managed to return it to a previous state as repair failed. today I started the desktop Dell vista and not wifi but connected to wifi router, at the same time I started my Laptop, both got to desktop and froze, couldn't use anything, eventually managed to get laptop to a previous state and have that working without the wifi, turned it off in case that was somehow the problem. However not having much success with desktop vista, can only use safe mode fortunately with networking, have tried to repair (with the Dell disk inserted), although it restarted a couple of times, didn't make any difference. got onto system restore in safe mode and tried restoring to previous time, tried on 3 restores and all of them failed. When I returned to normal mode just have a black screen with a cursor and obviously can't do anything, so have returned to safe mode with networking.
I have therefore 2 problems, 1 - why it did it in the first place and will it do it again (laptop), suspect got something to do with networking and 2 - how do I get vista back in normal mode or do I have to do a complete new install with Dell disc.
Would be grateful if anyone can help.