Can't enter windows xp or safe mode

Hello,
I have the following problem with a friends PC: It won't enter in Windows Xp(after the "Welcome" screen apears a black background colour with the mouse pointer in the center and in amount of 2-5 seconds the PC restarts).If i try to enter in safe mode(of any kind) it hangs a bit at agp440.sys then the PC restarts itself.
Don't know what to do...tried to replace MOBO, verified the RAM(tested and re-tested,changed the position),changed the video card.
I'm thinking on reinstalling the OS, but this is for the last option.
Don't know what to do anymore....any sugestions...advices?...I have read that it could be a virus too, or maybe the hard drive. I scaned the sistem for dos and found some trjans and deleted them...but don't know what to do further..

 

Hi boby19166 and welcome!

Check out this possibility.

I also see reports of a defective Mouse causing this, believe it or not.

 

Would This be familiar?

 

Pandemic I'd say.

 

Hi & thanks 4 the support. I have talked to my friend and asked for more details, so I will share info with u guys...so........I'll start with the begining: He said that his pc was working fine until one day when he turned it on the pc had no sound(the sound driver dissapeared don't know how) and the display was like when you don't have installed any video driver.After this he told me that he restarted the Pc and then it worked fine. This happened several times and he "resolved" the problem with a restart. The day before yesterday he came to me telling that his pc is continuosly restarting and can't enter in windows or safe mode. I scanned the pc with some antispyware/antivirus programs and found some trojans and suspicios files and deleted them(the infected files were some of his personal data, not from windows). I have tried what u indicated me in the post, but didn't worked, neither the linked post didn't help...that was different problem that mine ...I tried schdsk /r, disable agp440...but with same result.
I will try to convince my friend to reinstall windows and i will post the result. the thing is that this happened before(dissapearing sound and like no video driver installed) and i adviced him to change his MOBO, and after that a couple of months everything seemed to work just fine until now.
Thanx again for help and for quick answering.

 

I also changed the mouse and keyboard with no results...i installed another video card from the same graphic chip manufacturer(ATI)...i thought it wold solve something , but....still no result.

 

I'll assume that's a typo error and you meant chkdsk /r. Ran properly, it would take several minutes to complete....did it? Since you ran it from a command line, you would also get a report on any errors it found and "fixed." Did you?

Did you get a confirmation message when you ran that command to indicate that the agp440 service was disabled?

If you answered yes to all of the above questions, then you are best advised to go ahead and reinstall XP. The trojan damage is likely the cause and since system access is limited, the reinstall is the way to go now unless there is critical data to be saved.

 

Yes...i tried all of that>disabled agp440.sys(and that's for sure )...runned chkdsk /r(it tooked several minutes to complete indeed)...there were a few errors, but they were fixed. As my last option...for now...is to reinstall win on the first partition...and if something else is happening after i will post it here & let you know about it. I would rather do a full HDD format and then reinstall, but my friend has 100+Gb of data on a 250Gb HDD and i do not have the posibility to back up all of his data....so...for now i will format only the first partition....my question is the following: For protection against viruses, spywares and stuff like that what would you recomend? Does Microsoft have some programs for it?...Windows Defender for example..is it usefull..or should i try something else..but at low cost?
10X again for the help. I appreciate it.

 

Safe Mode

Try going into the bios and resetting the bios back to factory defaults and save.
Ti get into safe mode try changing or taking out a piece of hardware - ram ,sound card, network card etc etc.

 

I tried all of this...resetted the BIOS several times...set to factory settings...I tried everything in bios..and tried to boot only with the basic configuration(MOBO+prcessor+ram+video+disk)...and nothing......as i'm typing i'm installying the OS on the "bad" PC ...I will post further info if something goes wrong.
Thanks again

 

So....I reinstalled Windows...and....it seems that the hard drive is the problem, because when i restarted the system to install drivers...at the loading screen with win xp the pc restarted itself, so i decided to try a HDD change to see if that will sole the problem. In adition i can say that when i reinstalled win i ran some antivirus program and ffound some errors: something like CRC checksum error, and some viruses, so i send the drive to warranty hopeing for a replacement. I will post more info when I'll get another drive(hopefully).

 

wrong post, sorry. (again? , see below)

 

wrong post, sorry

 

So...first of all I appologise for this late post. Finally they replaced the hard disk...and a reinstalled windows..after this evgerything is ok...my friend is relaxed now that he hasa new HDD. Again...sorry for so delayed posting...that was because the hardware supplier had some problems with the cargo at the customs(that's what they told me).

In conclusion...the problems was a Maxtor disk drive, wich now is replaced and it's going ok.
Thanks 4 the support!