Hi I am a newcomer to Techspot but after having a good look around other posts I wondered if someone could help me with a PC problem I haven't experienced before. If it helps, I'm using a Dell Dimension 3000 desktop. The service tag has "JND5T1J" on it. There is also a yellow sticker on there which says "Windows XP Home Edition U7670" My problem is that I have started to receive some pretty strange error messages shortly after startup and whist using the computer. This all started a couple of weeks ago and since then my PC has been extremely slow. Sometimes I can't even start up properly - after the logon screen Windows often freezes at my screensaver and my shortcuts don't even appear. On the occasions that it does start up OK, some shortcuts often don't work at all and the internet takes an age to even come up. In addition, two desktop shortcuts for programs which I have never downloaded have appeared - one is Windows Updater, the other I am afraid I cannot remember at this moment. At the foot of this post I have provided details of the error messages I am commonly getting. I assumed that my PC was suffering from virus/spyware/malware and had a good look at the guidance provided by Julio in the thread entitled "Viruses/Spyware/Malware, preliminary removal instructions". I have run Windows Defender, Spybot Search and Destroy and Ad Aware and deleted loads of infections which were found. When the problems persisted, I started following the instructions at the above link to the letter, from the beginning. This included using TrendMicro's Housecall, Hijack This, CClean etc. However, I am now getting further and further into unknown territory and am fearful of doing further damage to my operating system. I wondered if anyone with more knowledge could guide me through how to tackle this problem once and for all. As much as I am enjoying learning and trying to proudly fix it myself, my inexperience could prove to be my downfall. The error messages I am experiencing are: (After startup) During a scan of files at system startup, potential errors in the system registry were found. p-07-0100 irql: 1f SYSVER 0xff00024 NT_Kernel error 1256 KMODE_EXCEPTION_NOT_HANDLED (While shutting down) Access violation at address 694C5405. Read of address 694C5405 (Randomly while on the web) RUNDLL Error loading C:WINDOWS\system32\jatarwkf.dll The specified module could not be found. If anyone can assist I would very grateful indeed. Many thnaks for taking the time to read my post.