I have a HP dx2400 PC, Intel Core 2 duo E7400 processor, 3.25GB ram, running XPSP3.
Until yesterday it appeared to be working perfectly. I installed nothing yesterday and noticed no unusual behaviour. When I booted up this morning the CAD drawing package that I use daily would not start and gave an error message saying that it could not find its security dongle. I tried to run Firefox, this started and then immediately froze, locking the pc so I had to restart from the power button. The same happens with Thunderbird and any other exe files I try. When I look in explorer at 'My Computer' I just get the egg timer and it will not show any files.
Everything works fine in safe mode, except the CAD software, however this uses a serial dongle on an expansion card so it may not work in safe mode anyway.
In safe mode I ran Malwarebytes and it found certain items which were removed. This made no difference. I have run full scans with stinger, spybot S&D and Avast antivirus, all report no errors.
I use the CAD software as a self employed designer so i am pretty desparate to get it up and running again. I would appreciate any help or advice please!!
Many thanks in advance,