Judging by the group's evolution I doubt there's anything left in their premises.
In the beginning it was a one man's show, Mr. Pouliadis formed the "Pouliadis and associates" company selling the Quest brand PCs. It was also the first official Microsoft distributor in Greece and developed the "official" Greek add-on for windows 3.x (official in quotes since it wasn't from MS themselves, but was the official solution for Greek characters in windows from the official distributor).
Win311gr.jpg
They had deals with the public sector to equip school labs (schools had just begun to offer computer classes) and civil service buildings. The first website dumb from way back machine is that of 1996, well into the Pentium era: https://web.archive.org/web/19961115033741/ht … t.gr/2index.htm
The Quest PCs were of really good quality, but around that time the market had grown enough for multiple companies to jump in, offering budget/cheap products. The company was healthy enough to adapt so they transformed into a larger group called "InfoQuest", entered the stock market etc. They continued selling their Quest PCs, but also created a cheaper brand (called "Plato"), expanded into the supplier-reseller domain, prepaid mobile telephony (called "Q", who would have thought!) and became the official distributor for more imported and well known brands. At some point they were the biggest supplier in Greece. At the small computer shop where I was working back then we were also getting all of our stuff from them and the owner had a personal relation with Mr. Pouliadis, I've met him once.
But it didn't last, it was a combination of bad decisions and the aggressiveness of the market during the late 90s. They went bankrupt around 2005-6, Mr. Pouliadis retired, assets were liquified (that's why I doubt there's anything left, I had friends working there during that time and I know that the buildings were basically empty when this process finished). After that the group (https://www.infoquest.gr/) continued to do business and it's still active, but apart from the name it has no real ties to the original company. Mr. Pouliadis passed away in 2011.