on stratup i keep geting a rundll error it say that it can not be found (kqayfdfh.dll) i can not found it in the reg system . so i take that it has been delated so how can i fix the problem i have done virus scan restalled all missing folders plus manual searched for the file can not found it .

Are you sure that you have spelt the kqayfdfh.dll correctly? There are no matches to it anywhere that i have searched. Can you get a PrintScreen of the error message?

Whichever it is, there are a couple of things that could have gone wrong. If it cannot find the 'registry' it is pretty problematic. If it is a specific *.dll, the easiest solution is to try a repair install. You can do this from your OS disk. just boot from your OS disk, and there will be an option to 'repair' your windows installation.
If you have your personal files 'protected,' then it will probably bring up some problems, but if you don't know if your personal files are protected, or if your hard drive is encrypted, I guarantee that it isn't.

It could also be that the filesystem on the hard drive is currupt. This can happen from shutting the computer off by just cutting the power, could be from hard drive wear, or just randomly. The easiest solution here is to do a full reinstall, and use the standard format option on the whole hard drive. Quick format will not fix the hard drive problem, a full format will mark bad sectors and automatically not use them.
If your hard drive has been currupted, and you need to recover files from it, there are some options.
If the curruption is only part of the filesystem, and the majority of the drive can still be written, there is a chance that you can use a PE disk to copy any crucial files. google BartPE, and try that.
If you are willing to spend the 80 bucks, google Spinrite. I personally swear by it. It will run through your hard drive, fix errors, set aside bad sectors, etc. It has saved my bacon several times before.

thanks for the info but have tryed all the above have repaired the os but could this be part of a program on my system an not the os i have put a screen shot of the error
thanks all dave

What Operating System are you running? It looks like Vista, but that's an old MS Word icon so i am guessing 2000? Please tell us your OS!

edit: On my PC XP, there is nothing matching that in the system32 Windows file. It could quite easily be a virus/spyware causing this error. What Anti-Virus and Anti-Spyware do you run?

the os is xp sp2was useing avast but got heaps of vurises so someone told me to ues avg but that slowed my my sys to a crawl so i put on ca anti vuris and spyware that has worked fine iam going to re still my prinrt to c if that work thank for every ones help on this preb thanks a million