Condensation between the panes means the perimeter seal on the insulated glass unit has failed and moisture is inside the sealed airspace. It cannot be cleaned, dried out or repaired. What it usually does not mean is that you need a new window.
What actually failed
An insulating glass unit is two or three panes bonded around the perimeter to a spacer, with a desiccant inside that spacer to absorb residual moisture. When the seal fails, humid air gets in, the desiccant saturates, and moisture condenses on the interior surfaces. The glass is fine. The frame is usually fine. The unit is done.
When the unit can be swapped
In most cases it can, and it is significantly less work than replacing the window. The conditions are straightforward: the frame has to be sound, straight and properly anchored; the glazing method has to allow the unit out, which systems with removable stops or gaskets are designed for; and a matching replacement has to be obtainable.
On commercial aluminum framing this is routine. On residential windows it depends far more on how the sash was built.
When it cannot
Some residential windows have the glass permanently bonded into the sash at the factory. There is no removable stop, and getting the unit out means destroying the sash. On those, the sash or the whole window is the replacement unit.
The frame can also disqualify it. Rotted timber, corroded aluminum, a bowed frame, or anchoring that has already failed all mean the new unit would be going back into something on its way out. And if the framing is obsolete enough that stops and gaskets are unobtainable, you can get the old unit out and be unable to secure the new one properly.
Matching the replacement
Overall thickness has to match, because that is what the glazing pocket was built for. Airspace, coating and tint should match too, or the replacement will read differently from the units either side of it — noticeably so on a flat elevation in daylight.
On older buildings the original coating is sometimes no longer made. A good contractor will say so before ordering, and will usually suggest doing a full bay rather than one pane so the difference reads as deliberate.
What about drilling and venting?
There are services that drill a failed unit, clean it and fit a breather valve. The visible haze often does improve. But you have permanently vented the sealed airspace, which is the thing that made it an insulating unit. The appearance comes back; the performance does not. For a building being assessed on energy use, that is not a repair.