1. You cannot of course leave that computer frozen on that apparent diskcheck. Although I am sure by now you will have forced a shutdown.
If NOT and it is still in that situation, please do shut it down.
2 The manual and other documents for the Dell Dimension 4700 as is the usual case do not list what MAKE of HDD is in that computer.
It is I think you will find a SATA drive. If we knew the make of hard drive then we could run the manufacturers utility in extended test to assure ourselves that the hard drive is, on the evidence available in a healthy state.
Although some of the measures already taken have run to completion, many of them, before you even started on the repair installation, have resulted in crashes and BSOD and I would like to make some checks on hardware.
3. If you feel competent to do so, I would like you to see if you can, ascertain the make of HDD. Here is the manual for the computerhttp://support.dell....m/Y69490LRs.pdf
Please see page 74 onwards.CAUTION
Working inside a computer requires special precautions for anti-static and a VERY careful following of the porcedures in that manual. IF YOU have never opened the case of the computer then MY ADVICE is to do ONLY that. NOT to attempt removal of parts.
When you have the case open - check visually the general cleanliness of the inside for dust and dirt.
IF THE INSIDE is clearly very dusty and dirty and the fans are covered in dust and the vents of the case are, then please post back for further advice.
In the meantime I will post with two programs I would like you to run.
One is a disk check that will run on any drive and the other is a test of the ram.